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2006 Volvo 780 surging while using Cruise Control

Parrformance

By Parrformance January 24, 2023 in HDT

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Parrformance.

I am suspecting a dirty/failing speed sensor cussing surging while using CC.

Perhaps someone else has experienced this and might have some tips?

In my mind I am thinking of checking and cleaning the sensors around the tail shaft of the Eaton ten speed with Autoshift.

2006 Volvo VNL 780, " Arvey"  Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift

2003 Jeep Wrangler Rubicon

2010 Forest River Coachman Freedom Express 280RLS

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Which engine is in the truck?  Is around same time frame as my 05 with C15 in it.  Does the Volvo have a Warm Up fast idle off cruise as Cat did?  Easy way to check of speed or tach sensor as the Cat also has Two Engine Speed sensors, one for Dash Ga and Cruise the other for ECM if does have that warmup rpm adjust.  I replaced my Trans speed sensor where cruise is fully functional now.

If suspect adjustment should jamb nut have loosened, run the sensor in to contact of trigger wheel, back out 1/2 turn.

Wrknrvr

    We have. 2000 Volvo. The cruise worked but not on big hills. It would wait till it had to pull hard to stay in the speed.

   So I just used the pedal to help the cruise control until it was doing its thing.

    I try to stay ahead of replacing things before they really are needed. So I ordered a throttle position sensor. Installed it.

     So I took the truck for a drive. It fixed my cruise problem.   Just by chance I guess.

Good tips, ddm502001: the truck has the Volvo 12.1, and does have the fast idle I can set with the stalk. I will fire it up this weekend and see if it will hold a fast idle in neutral. Great way to isolate the speed sensor from the ECM Crank speed sensor 👍🏽

The truck CC has worked flawlessly since I bought it, this is a new issue.

I am suspecting a dirty or corroded speed sensor that is intermittently giving good signal then dropping out.

Feels as though the truck thinks it is going up hill then downhill in just a few seconds.

If you can stand it, it will actually maintain the relative set speed albeit surging up and down.

Truck runs fine and smooth with the foot throttle.

Wrknrvr, I do plan to swap the sensor with new (from the dealer if available)as soon as I isolate it 👍🏽

I have an additional symptom to narrow down the offending circuit.

While searching the World Interwide Webasphere for a moving picture pertaining to the Eaton Fuller 10 speed with Ultrashift II, my memory got jogged to a couple of instances of abnormal shifts.

While traveling home last trip, after exiting the Interstate system from a prolonged steady 65 mph travel, the transmission remained in a gear longer than usual.

This occurred on an up shift as well as a down shift.

The video was referring to a couple of sensors on top of the tranny, one ☝️ bout speed, front right side of the x y shifter, and I think one rear left of shifter assembly.

I will check and clean all these sensors as soon as I can, hopefully by Saturday, and report back. 👍🏽

SuiteSuccess

SuiteSuccess

2 hours ago, Parrformance said: I have an additional symptom to narrow down the offending circuit. While searching the World Interwide Webasphere for a moving picture pertaining to the Eaton Fuller 10 speed with Ultrashift II, my memory got jogged to a couple of instances of abnormal shifts. While traveling home last trip, after exiting the Interstate system from a prolonged steady 65 mph travel, the transmission remained in a gear longer than usual. This occurred on an up shift as well as a down shift. The video was referring to a couple of sensors on top of the tranny, one ☝️ bout speed, front right side of the x y shifter, and I think one rear left of shifter assembly. I will check and clean all these sensors as soon as I can, hopefully by Saturday, and report back. 👍🏽

I assume you are referring to the input and output sensors on the transmission?  If so be very careful removing them (if you can). They are plastic and if original VERY brittle. Supposed to be a 15 minute job to change out but took GeorgiaHybrid and I 9 hours after the output sensor literally crumbled leaving pieces down in a hole. I do know the output sensor has several “holes” to mount the sensor and you may be better served just mounting a new one in another hole and just leaving the old as a plug. BTW my truck is also a D12 with 10 speed.  Also beneficial to coat with some antiseize for future. 

2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift

Bed Build by "JW Morgan's Custom Welding"

2017 DRV 39DBRS3

2013 Smart Passion Coupe "Itty Bitty"

"Don't go around saying the world owes you a living. The world owes you nothing. It was here first!"

The video I referenced also stated not to bother removing the old sensor.

👍🏽 Thanks Suite 👍🏽

On 1/25/2023 at 6:47 PM, Parrformance said: The video I referenced also stated not to bother removing the old sensor. 👍🏽 Thanks Suite 👍🏽

Get it figured out yet?

Just finished it up today 👍🏽

I’ll preface it by saying I chose to clean and dialectic all the connections at the transmission. Once I pulled a couple of connectors apart only to find pristine contact points, I decided to pull the plug out of the top port of the tail shaft.

I noticed a LOT of powdered rust and debris came out with the plug.

This prompted me to pull the lower plug as well.  Rusty powder poured out like water, the tone ring inside however was shiny clean.

I was hopeful this was the cause of the surging, but I chose to reach out to Nextran the local Volvo dealer to see if they had a new sensor in stock.

Mike said we have 1, quoted $47 so I put everything back together enough to drive the truck over to get it.

The cruise was somewhat better on the way over but not perfect.

I took the tools I needed and had the port cleaned and prepared with anti-seize so I could slide under and install the new sensor as soon as I had it in hand.

The drive home was exceptionally pleasant, the sensor corrected the surging cruise control completely, and improved the shifting of the truck.

The shifts are smoother, and seem to be at the appropriate timing.

With your advice Suite, I am planning on leaving the old sensor as a plug, Thanks for the advice, this made the job quick and painless.

U0nZG2Vl.jpg

This the bulletin I found.

Good job.  Just wish I had been smart enough not to remove the old sensor.

MG82Mt9l.jpg

This is what mine looked like after “attempted “ removal.  The top fuzzy picture is the remnants in the hole that took David and I hours to clean out.

GeorgiaHybrid

GeorgiaHybrid

Nothing like laying on your back, pick in hand, flashlight in your mouth with a mirror held by someone else to see what you are doing while trying to fish out 100 feet of wire and bits of crumbled plastic out of a hole in the top of the transmission.

Fun times....

2017 Kenworth T680 2015 DRV 38RSSA Elite Suites 2016 Smart Prime

25 minutes ago, GeorgiaHybrid said: Nothing like laying on your back, pick in hand, flashlight in your mouth with a mirror held by someone else to see what you are doing while trying to fish out 100 feet of wire and bits of crumbled plastic out of a hole in the top of the transmission. Fun times....

Hey David, let’s do it again.  This time I might even bring the beer since it may be a shade longer than 15 minutes!   😜

lappir

3 hours ago, SuiteSuccess said: Hey David, let’s do it again.  This time I might even bring the beer since it may be a shade longer than 15 minutes!   😜

You guys seem to have all the fun. 

White 2000/2010Volvo VNL 770 with 7' Drom box with opposing doors,  JOST slider hitch. 600 HP Cummins Signature 18 Speed three pedal auto shift.

1999 Isuzu VehiCross retired to a sticks and bricks garage. Brought out of storage the summer of 2022

2022 Jeep Wrangler Sport S Two door hard top.

2007 Honda GL 1800

2013 Space Craft Mfg S420 Custom built Toyhauler

The Gold Volvo is still running and being emptied in July. 

A wise man accept instruction from others with a good attitude 😁

Thanks to you all, it was a 15 minuteish job 👍🏽

https://www.amazon.com/gp/aw/d/B07Y21PLQM/ref=ya_aw_od_pi?ie=UTF8&psc=1

18 hours ago, Parrformance said: A wise man accept instruction from others with a good attitude 😁 Thanks to you all, it was a 15 minuteish job 👍🏽

Oh yeah, Parr, rub it in 😂 (Just kidding).

It was most definitely meant as an appreciative compliment, I was thankful for the advice to leave the old sensor well enough alone.

I was more than happy to learn from your adventure.   

I am quite surprised how much smoother the shifts feel, it had always shifted firmly. Having never driven an HDT with an Ultrashift I assumed it was supposed to be like that.

Well maybe just a little salt 🤣 just kidding my friend, Thanks for the tip 👍🏽

3 minutes ago, Parrformance said: It was most definitely meant as an appreciative compliment, I was thankful for the advice to leave the old sensor well enough alone. I was more than happy to learn from your adventure.    I am quite surprised how much smoother the shifts feel, it had always shifted firmly. Having never driven an HDT with an Ultrashift I assumed it was supposed to be like that. Well maybe just a little salt 🤣 just kidding my friend, Thanks for the tip 👍🏽

BTW did you change out input and output speed sensors or just one?

Just the output, seems as though things are working well currently.

I will likely not mess with the input if things continue to work well.

On 1/30/2023 at 6:24 PM, Parrformance said: Just the output, seems as though things are working well currently. I will likely not mess with the input if things continue to work well.

Thank you again Suite for the sound advice 👍🏽

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Crusie Control on Volvo 700, 900 and 90 Series

Cruise Control Won't Work or Incorrectly Disengages/Re-engages: Diagnostics

Cruise Control Surges: Worn Servo

Cruise Control Onboard Diagnostic Codes

Cruise Control Installation Instructions for 740 Cars

Cruise Control Won't Work or Incorrectly Disengages/Re-engages

Vacuum Diagnostics:

Basic Diagnostics. My cruise control stopped functioning. Where do I start? [Jay Simkin] When cruise control malfunctions: (a) vacuum pump and cruise control module not likely to be a source of trouble; (b) throttle servo (black rubber bellows) and vacuum lines merit a quick look; (c) turn signal wiring and cruise control switches on the turn signal stalk should be checked first, as it is easy to access. [Vladimir Ferdman]

  • Check the vacuum system integrity first. If this checks out proceed to 2. Otherwise find the source of a leak in the vacuum system. Mine was in the brake pedal switch, which I guess is common. I found my vacuum pedal switch/valve to not hold vacuum.
  • Perform OBD tests regarding the cruise control. The OBD system is very good and will often pinpoint the problem.
  • If all the above checks out good, then test the vacuum pump.
  • A very last resort is to question the control module, but these rarely fail.

Vacuum Servo Diaphragm Bellows and Lines. [John Randstrom] I have found that the vacuum servo diaphram that pulls the throttle open can spring a leak. I usually check these first, along with all of the electrical connections and vacuum lines and valves that are mounted to the brake and clutch pedal brackets. Check all the vacuum lines and the servo with a Mityvac tester and if they hold a vacuum, you have no leaks. If these valves do not seal with the pedals in the rest position, the vacuum will be bled from the servo and the cruise will not engage. ]Philip Baugh] I recently had the cruise control go out on my 1994 944 and 945, so I thought I would share how I fixed each. Using my mighty vac I traced the problem on my 944 to a pinhole leak on the cruise control bellows under the hood. I cleaned the rubber bellows and applied a small inner tube patch. [Editor] The bellows can leak where it contacts the edge of the throttle position switch and develops a wear groove.

Split Hose or Misadjusted Switches . [Response] Most common problem that I have seen is either split or disconnected vacuum hose, or mis-adjusted brake switch (at the pedal) or clutch switch (if manual tranny). Sometimes it is simply that the brake or clutch pedal is not fully returning - try lifting up on the pedal with your foot while driving and see if you can engage the cruise. In addition to the vacuum switch, check for operation of the brake light switch. I seem to remember that the vacuum switch will disengage the cruise simply by releasing the vacuum from the unit, but the brake light switch must activate in order to release the control unit signal. If you are just tapping the brake lightly to disengage the cruise (as I often do), but not activating the brake light switch, then it may simply re-engage as soon as vacuum is applied again.

Applying Vacuum to Locate Leaks. [Response] Pull hose loose at "T" fitting aft of throttle servo or at the vacuum pump . Apply vacuum (suck on it, but make sure no one's watching) to fitting with hoses that run down to pump and into car to brake pedal defeat switch. Watch the rubber servo bellows which should collapse and hold vacuum. If leaks are detected here then find split hose or go inside and find pedal switch fault. Or closely inspect the servo for splits or tears. The likelihood of electrical trouble is far lower than having a hose split or a leaking servo. See below for information about the vacuum pump. [Editor] On 940 cars, an easy vacuum system test is to disconnect the vacuum line at the back of the bellows on the throttle. Using a Mityvac, test the bellows for leaks. Then apply vacuum to the line you disconnected while placing a finger on the white bottom air vent on the vacuum pump. The system should hold vacuum. Have a helper press the brake pedal which should release the vacuum. Remember to replace any vacuum hoses you might have disconnected.

Mechanical Diagnostics:

[Response: Robin Roemisch] My 740's cruise control throttle cable had come unwrapped from the spool. Its easy to catch if you're messing around the throttle body, and it comes off rather easily. Just wrap it back around and that should do it

[Response: Gene Stevens] In addition to the list John noted, two things I'd check first are brake light operation (#5 on his list), as every manufacturer uses them for a ground circuit path to the cruise controller, AND the item that made me a little crazy on mine... There's a vacuum release valve on the brake pedal that can bind a bit with age. Hold the brake pedal up with one foot while you engage the cruise control. If it now works properly, the release valve my be slightly open. Mine would vary speed on certain days, opposite of the way you'd expect. Flat ground would occasionally lose about 1 MPH per minute and settle in about 8-10 MPH below set speed. Start going uphill, and the car accelerated back to the set speed, and maybe/maybe not, do the 1MPH/minute thing again after getting level again. Going downhill would cause a faster drop in speed (odd, huh) and creep back up on level ground. The final answer was that the tilt of the car going up and down hills changed the effective weight on the brake pedal. Lift the pedal, and rock solid speed every time.

[Response] There is a separate switch with a vacuum line attached for the cruise. If the car is manual tranny, the car would have two switches, one for each pedal. If the switch adjustment is marginal, i.e., there is not a definite "off", then the switch needs to be adjusted. It is adjusted the same way as the brake switch.

Electrical Diagnostics:

[Inquiry] My cruise control in my 1990 740 has failed. Vacuum hoses are fine. How do I test internally for the problem related to the push button control button attached on the turn signal lever?

[Response: John Sargent] Before you start checking the switch, lets do the easy electrical circuit tests.

  • Is the yellow speed signal wire connected to the back of the speedometer? [Editor] Depends on model: could be orange/green etc. Check the wiring diagram.
  • Are the brake and clutch switches properly adjusted and carrying electricity? The brake and clutch switches get power from the brake light switch. Terminal 3 at the control unit should have power from the brake and clutch switches.
  • Is fuse # 10 good? Is there electricity to the unit? Terminal 1, blue-red.
  • Are both brake lights working? The cruise control supervises the stop light circuit, and if the stop lamps are bad, or the lamp failure relay dies, the cruise control will not work. [Note from John Sargent] There is a reason for this. The people who designed the cruise control did not want the cruise control to work if there was no input from the brake system to shut the cruise control off when stopping. The cruise control imparts a very small voltage to the brake light circuit. A very small amount of current flows (this is referred to as a supervised circuit) if the circuit is connected. A failure of the bulb failure sensor can have the same effect as having both stop lamps burnt out. As a result, if both your brake lights and your cruise control fail, then take a hard look at the bulb failure sensor.
  • Check the wiring connections to the vacuum pump. Pull the hose off the vacuum pump and suck on it. The servo should operate the throttle.
  • Is the turn signal unit plugged in? Remove the covers behind the steering wheel and inspect the electrical wiring for breaks. See the FAQ section under "Instruments" if you need to replace the stalk .
  • Is the control unit plugged in? The control module is on the left side, under the driver's side kick panel
  • Terminal 1 of the switch carries power to terminal 2 of the switch in the On position. Check for +12V at the control unit connector at terminal 11 (Blue-Orange) when the switch is "on" and ignition "on". Or check resistance between terminals 11 (Blue-Orange) and 3 (Orange-Black) which should be infinite in all but "On" or "Resume".
  • Terminal 1 of the switch carries power to terminal 4 of the switch when the speed button is pushed (momentary contact). Check for continuity at the control unit connector between terminal 6 (Blue-Green) and terminal 11 (Blue-Orange) when "Set" is pressed and cruise is "on" or "resume" In any other position (Cruise off and Set pressed or Cruise On and Set is left untouched) check resistance which should be infinite.
  • Check the brake/clutch vacuum switch electricals by disconnecting the connector and measuring resistance between the switch pins. This should be "0" when the pedal is Up and infinite when pedal is pressed more than 8 mm.

Brake/Clutch Pedal Switches:

[Editor] There are two cruise control switches on the brake pedal: an electrical on-off brake light switch and a brake valve/switch. If you have a manual transmission, this latter will also be on the clutch. The brake light switch cannot be adjusted and can merely be tested for continuity ("on" when the pedal is depressed more than 8mm as above).

The brake vacuum valve should normally be closed and must not leak when the pedal is up. The brake valve comes in two varieties: an older style with a threaded plunger and a newer style with internal plastic catches on the plunger. With the pedals up, the valve is activated, the spring is compressed, the switch is on, and the vacuum valve is closed. The older brake/clutch valve can be adjusted (to about 1 to 1.5mm play between the plunger and the pedal arm) by removing the connectors and turning the valve to the correct play. The newer one has plastic catches in the plunger that hold it correctly: if these fail, replace the valve. Leaks in either valve or at the couplings require replacement or repair as noted above. [Vladimir Ferdman] I found my vacuum pedal switch/valve to not hold vacuum. Removing the switch and disassembling it revealed the o-ring not fitting the plunger snugly. I wrapped two layers of teflon tape on the plunger and reassembled. This fixed the vacuum problem. I then retested and the vacuum held.

Vacuum Pump:

[John Sargent] The cruise control on 940s does not use engine vacuum but rather a vacuum pump.[Vladimir Ferdman] Apply 12V to the bottom terminal and GND to the middle and top terminals at the same time. This should activate the pump and the vacuum control valve at the same time and cause the servo at the throttle to contract. If the GND is removed from the middle, but left on the top terminal the servo should stay contracted and hold vacuum when the pump is off. [Al Sichelstiel] Odd occurrence requiring a lot of diagnostic work: the cruise system would initially engage then disengage, as though a vacuum leak or a bad switch were at fault. The cruise would momentarily engage pulling the diaphragm into operation then lose vacuum almost immediately. After much diagnostic work, we found that there is a pressure switch inside the vacuum pump assembly that measures the vacuum level and bleeds off or increases the vacuum as needed. That switch in the pump assembly failed and was dumping vacuum at almost the instant the system engaged. Swapped out the vacuum pump assembly and it worked fine.

Speedometer:

[Editor] When the cruise in my son's 95 940 failed, I performed the diagnostics thanks to the OBD unit under the hood. It returned "no signal from speedometer". The speedometer and odometer were working fine. I tested the output from the speedo using a multimeter and it "appeared" to be working. After making sure everything else was working, I finally replaced the speedometer and cruise returned to normal. It so happens that the speedometer receives a sine wave signal from the rear axle sending unit and converts this into a square wave, with frequency proportional to rear wheel velocity, to serve as a the input into the cruise control computer. If this does not happen, no cruise control. I do not have an oscilloscope which would have made quick work of this diagnostic. Anyway, if your cruise dies and you get this diagnostic report while your speedometer appears to be working fine, consider that the internal wave conversion might have failed. This means a replacement speedo.

Cruise Control Surges: Worn Servo .

[Inquiry:] What is the fix for surging with the cruise control ON. It tends to fluctuate 2-4 mph in level driving conditions. Real annoying.

[Response: Abe Crombie] Look closely at the servo on the throttle housing that tugs the cable wrapped around the throttle spool. This can get a hole worn in it and the vacuum level that keeps throttle positioned evenly is impossible to maintain. Try repairing with a bicycle tube tire patch.

Cruise Control Onboard Diagnostic Codes .

[Editor] Later LH2.4 cars employing two diagnostic modules can directly read cruise control codes. Plug the module pigtail from the "A" unit (this unit has the pigtail connector, the test button, and the LED readout lamp) into position two on the "B" unit. The cruise control system for earlier LH2.4 cars without a "B" unit can be connected to the OBD system to read diagnostic codes. To do this, run a wire from the extra pigtail on the cruise control unit connector at the left side under the driver's kick panel to the OBD diagnostic connector in the engine compartment (the pigtail you plug into the various holes.) The system must be tested with the ignition "On" and after roadtesting above 35 km/h (22mph) since the unit does not store codes, only reports them, and erases all codes when the ignition is turned off. The following is a brief excerpt from the OEM manual.

There are two diagnostic modes:

  • Ignition "On" after roadtest, diagnostic wire connected. Press diagnostic button once for one second. Read the code.(If nothing flashes, see No Code .)Check for another code by pressing again for one second. Repeat until the first code is returned. This test returns various error codes from the road test.

With Ignition & Cruise Selector "On"

  • Mode 2: Component Test
  • Ignition "On", diagnostic wire connected. Start with cruise selector switch "Off" and the transmission in "Drive". Press the diagnostic button twice, each for one second. The LED should flash rapidly. Then perform the following tests in the order listed to test each component of the cruise control system. Faults may be pinpointed to the components or circuits noted.

Cruise Control Installation Instructions for 740 Cars . [Procedures from John Sargent]

All US 700 series Volvos come pre-wired for installation of cruise control at the dealership. Australian market 700 series, and possibly other market 700 series, do not come pre-wired for cruise control. The following instructions are for US market cars. Volvo used components from Hella on the 700 series cars, as well as 1986 and later 200 series. These instructions assume that you have the components in hand.

The following is a list of the components:

  • Turn signal control with cruise control function
  • Vacuum servo, two 10mm head bolts
  • Vacuum pump and regulator, 3 mounting screws
  • Control unit
  • Air valve. Automatic transmission cars use one. Manual transmission cars use two
  • Rubber tubing, and tees.

There are a few model year differences in components.. The brake and clutch switches and their respective sockets for the 1985 and earlier models are slightly different. 1991 and later 740 use a different turn signal assembly to match the dashboard change. All 760 series come with cruise control, however the 760 series uses the different turn signal assembly with the dash change (1988). If you are scrounging parts, the turn signal assembly and brake /clutch switch(es) is the same on 6 cylinder cars and diesels. I have not tried it, but the CPU will probably interchange. The servo uses the same rubber parts on the diesel, but the bracket is different. I don't know if the 16 valve 740 uses the same servo and throttle pulleys.

Turbo and non-turbo use the same servo, throttle assembly, and control unit. The components will interchange between the model years except as noted above.

You will need a Phillips head screwdriver, an 8 mm and a 10 mm ¼" drive socket, a ¼" drive 3 inch extension, a ¼" drive ratchet handle, and a knife. On later cars (1990 on ?) you will need Torx tips to remove the steering column trim.

  • Remove the trim panel above the driver's feet. It is retained at the top by 2 Phillips head screws along with a plastic plug, and another plastic plug just above the hood release handle. The plastic plug just above the hood release does
  • Install the control unit. It installs just outboard of the hood release cable and the bundles of factory wiring. You should find a wiring connector with 8 wires, and one with 1 wire. Plug the wires into the unit. The 8 wire connector is polarized and will go on only one way. There are two nail head studs on the outer body panel. The bracket has keyed holes on it for installation on these two studs. The wiring connector end goes down. Optional is the installation of one self drilling screw at the front of the bracket. Both dealer and factory installed cruise controls are often anchored this way. I don't bother.
  • Install the brake switch, and clutch switch if manual transmission. Remove the metal clip and slide the switch into the hole provided. Install the retaining clip. Check the adjustment of the switch(es) with an electrical meter. I like to just tap the brake pedal and have the cruise control disengage. Plug the wiring harness connector into the switch(es). The connector is white and has a white/black and a blue/red wire. You may have to examine the area closely to find it, as it may be tucked into the other wiring in the area above the brake pedal. If the car has a manual transmission, there will be a connector for each switch. In this case, one connector will have two blue/red wires. The switches are in series, so which connector goes to which switch does not matter.
  • Route the vacuum hose through the large rubber plug in the left side of the firewall. There are several nipples cast into this plug. Cut the end off of one of these nipples for routing the hose. Some people route the hose through the hole filled by a single rubber plug. Connect the hose to the brake and clutch switches. A tee fitting is provided for cars with two switches. The vacuum portion of these switches will disengage the cruise control in the event the vent solenoid valve in the vacuum pump fails.
  • Install the vacuum pump. Your 8mm socket will drive the three small hex head sheet metal screws. There are three holes pre-drilled at the top of the reinforcing metal on inside of the left fender well, just under the brake master cylinder. Connect the wiring harness connector to the vacuum pump. This connector is gray, and has three wires in it. Sometimes this wiring harness is well buried with the wiring to the left headlights. If you look, you will find it unless (unlikely) that is has been removed. Connect the vacuum hose you just routed through the firewall to the rear (black) hose nipple on the rear of the vacuum pump. Install the tee fitting near the pump. The tee fitting will connect to the hose from the servo. The front hose nipple is not used. It may be necessary to move the power steering hoses forward from the area where the where the vacuum pump mounts. This is made easier by removing the engine air intake hose, but is not necessary.
  • Install the turn signal assembly. If your car is air bag equipped, remove the steering wheel trim. Next, remove the old turn signal unit and install the new unit with a right angle screwdriver. If you don't have an air bag, it is easier to pull the steering wheel. Connect the 4 wire gray connector to the short wire harness from the turn signal assembly. Sometimes this connector is well hidden. If you can't find it, it is often incorporated with the harness connected to the turn signal. Sometimes it is easiest to remove the instrument cluster to do this. While the instrument cluster is out, check to see that there is a yellow wire connected to the back of the speedometer. This is the speed pick up for the cruise control. The yellow wire is always connected at the factory, but could become disconnected with instrument cluster replacement, or service light resetting.
  • Install the servo on the intake manifold. Use your 10mm socket here. It is installed utilizing two tapped holes that are behind and below the throttle pulley assembly. Be careful not to pinch or kink any hoses between the manifold and servo. Connect a vacuum hose between the tee at the vacuum pump, and the servo.
  • Replace the throttle pulley assembly with the new unit. Use your 10mm socket here. This can be done without removing the snap ring holding the throttle pulley assembly together. Just twist the guide ring to the proper position, and the cable end will drop in. If you have to remove the snap ring be careful not to lose the pieces. Connect all three cables. Adjust the cable slack if required.
  • Go for a drive. Trouble shoot and adjust as necessary.
  • Replace the trim panel above the driver's feet. Don't forget to connect the heater hose

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Cruise Control Stopped working

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Anyone had their cruise control just stop working with no other symptoms or issues? Any suggestions on where to look? It turns the "cruise" indicator on, but won't set. Thanks 2004 Volvo S60R Automatic  

alexk243 said: Anyone had their cruise control just stop working with no other symptoms or issues? Any suggestions on where to look? It turns the "cruise" indicator on, but won't set. Thanks 2004 Volvo S60R Automatic Click to expand...

z2000

I had similar issue that I was change brakelight to led. After I changed back the cruise working again. Sent from my BBF100-6 using Tapatalk  

I don't know if it might be related to the throttle body issue you have expressed in your other posts, but for sure if its the brake pedal sensor it will disable the cruise control. The brake pedal sensor is a cylinder mounted on the brake booster to the left of the master cylinder. It detects whether the brake pedal is being pressed or not. If it is not working, it will set both a BCM and and ECM code.  

Ok, Ill check it out with VIDA and see what codes are stored. I would be surprised if it was TB related as that has been going on for a while with no problem with the cruise control.  

My XC70 which I'm selling has never had the cruise control working, no light on dash, no codes in Vida, no idea why....  

This may work. My mechanic did this on my 94 945Ti when the cruise stopped working. Take the hose off the vacuum on cruise control module and use vacuum suction on the hose. It seemed to reset the module. Release pressure then hook it back up. I don’t know the schematic of our R but it may be similar unless ours is electronic then all bets are off.  

I heard the clutch position sensor can also kill cruise control. M66?  

Paisley Pirate

OP said it was auto, but on a manual car you'd be correct. I'd use Vida to look at what Vida is saying for switch positions on the brake, the parking brake etc. I'd also use it to look at the steering wheel pushbuttons and make sure that their signal is getting through. Could be clockspring in wheel causing a problem. Sent from my BBB100-1 using Tapatalk  

yeap, i had the same problem, just stop working like alexk243 said. Just put a new clutch position sensor, resolved!  

jrach

Yep, I had the same problem on my T5M, took apart the clutch pedal sensor, cleaned it, rebent the contact pins and I had working cruise control for a whole $0.00 Sent from my LGMP260 using Tapatalk  

So before I got to run any tests it randomly started working again... Not sure what to make of that.  

These are the typical symptoms of a failing brake position sensor. It needs to be replaced. It's located on the brake booster. There are at least two different variants depending on whether you have STC or DSTC. Get the correct version.  

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Volvo vnl cruise control not working

Discussion in ' Volvo Forum ' started by goranvolvo , Mar 7, 2013 .

goranvolvo

goranvolvo Bobtail Member

yes i can rise rpm up down no codes i do have dealer tech tool with laptop so i did road test and no problems shown .  

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bravoo67

bravoo67 Light Load Member

my friend has a volvo with volvo D12 and was explaining it to me since I have exactly the same problem but I never got it to work really.. so what he said was : before moving the truck and after releasing both brakes he presses the brake pedal all the way down, up to some pressure point on the gauges.. only after that hes able to engage cruise control while on the road It never worked for me though :/ hope it helps good luck!!  

Pablo-UA

Pablo-UA Road Train Member

do not look for cruise problem in engine ECU. After 1998 Volvo use VECU to controll engine (not with N14 and early Series 60). So no difference what engine you have, all switches in cab are connected to VECU  

Tam_Tam

Tam_Tam Light Load Member

Before we sold it our VNL (2006 EGR only D16) was "hunting". It would jump and drop about 50 RPM everytime we used the cruise, rapidly over and over. It was the engine computer. To completely fix this we needed a new ECM.  

ah fai

ah fai Light Load Member

Hello, i am facing same problem with 2 of my FM12 truck , i think i will try to replace a good working condition VECU tomorrow and see....  
It is working now I was testing every wire and sensor took the truck for test drive and it is working now So Check switch on brake and clutch pedal there is also air switch connected to the cruise it is on the left side off the clutch pedal pull the plastic panel off you will se it on the right top, check speed sensor  
Funny thing, cruise control working only when the truck reverse, stop work in forward...  

gregor

gregor Light Load Member

i had that thing too, i solved this by replaced the V shape spring which holds clutch pedal in top position, you need to remove plastic panel on the left side to the steering column, spring costed me 8.67$ ,plus mechanic adjust a bit little bolt in service brake valve ( under hood on firewall ) ,thats it !! problem solved, try this it might help  
thanks for advice..  

Danisuba19

Danisuba19 Bobtail Member

So what exactly did u do to make it work? I have the same problem, I would appreciate the help.  
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5 Reasons Why Your Cruise Control Stopped Working

Magnus Sellén

  • Updated: March 15, 2023

Cruise Control Not Working

It would be difficult to find a vehicle on the road today without cruise control. This invaluable feature makes driving long distances easier but can also cause trouble when it malfunctions. Understanding the reasons your cruise control stopped working ensures that you can get the problem fixed quickly for a more enjoyable ride. 

While this fault can cause issues with the cruise control system itself, there could also be an effect on the acceleration of your vehicle. That’s why you want to have it looked at as soon as you notice a problem. Let’s take a quick look at the reasons your cruise control may have stopped working.

Reasons Why Your Cruise Control Stopped Working

The most common reason a cruise control stops working is due to a blown fuse or a defective brake pedal switch . It can also be caused by issues with the throttle control system or the ABS. In older cruise control systems, it can be caused by a broken vacuum line.

Here is a more detailed list of the possible reasons your cruise control is not working:

1. Blown Fuse

Broken Fuse

All electrical systems in the vehicle are controlled by fuses. Your cruise control system is attached to a fuse that can blow if there is a short circuit or fault. Without a good fuse, the cruise control system can’t work at all.

Thankfully, it’s not difficult to find and replace a blown fuse. Look in the owner’s manual to find the fuse that corresponds with the cruise control technology. 

2. Defective Brake Pedal Switch

Push Brake Pedal

The brake pedal switch is responsible for turning the brake lights on and off based on the pedal position. Cruise control systems are designed to disengage whenever your brake pedal gets pressed. 

Because the cruise control is wired into the brake pedal switch, any fault can cause it to stop working. When the brake pedal switch malfunctions, the car believes the brakes are engaged, causing the system to turn off automatically. Not only that, but your car’s brake light might also be stuck on, leaving confused drivers in your wake. 

3. Malfunctioning Speed Sensor

Abs Sensor Close

Speed sensors are located on every wheel or differential. The purpose of these sensors is to monitor the speed of the wheels to determine if traction control is needed. 

The speed sensors are also part of the cruise control system. When a sensor fails, the cruise control can stop working and the speedometer might act strange as well. 

If there is an issue with a speed sensor, it will often show with an ABS warning light or a check engine light on the dashboard.

RELATED: 3 Symptoms of a Bad ABS Wheel Speed Sensor

4. Electrical Issues

Cruise Control Buttons

The cruise control system is electronic, with many components working together to make the system operate. If the cruise control fails to work, you want to check the wiring harness and associated connectors for a fault.

You also need to ensure that the voltage source is supplying enough power to the system. Even the smallest fault can cause defects with the cruise control. In many cases, there can be an issue with the cruise control lever or buttons causing the cruise control to not engage.

If your cruise control buttons are located on the steering wheel it could also be caused by a bad clock spring, which is located behind the steering wheel.

Check the system with an OBD2 scanner to look for any trouble codes related to the cruise control.

RELATED: 5 Symptoms of a Broken Clock Spring, Location & Replacement Cost

5. Damaged Vacuum Actuator, Hoses or Cable (Older cruise control)

If you drive an older vehicle with cruise control, you might have an issue with the vacuum actuator or the cable that connects to the throttle. If there has been damage done to the vacuum hoses or the actuator, the cruise control will stop working altogether.

Additionally, the cable linking the actuator to the throttle must be in good shape. If it has been broken, the cruise control will fail. 

What is Cruise Control?

Cruise control is a feature that is used when you are traveling at a consistent speed. Cruise control was first introduced for automobiles in the 1950s. However, it took many years before it became a staple in the modern vehicle.

This electrical system allows you to set a predetermined speed and take your foot off of the gas pedal. If you are on a long drive, there is less fatigue because you don’t have to try to maintain your speed. Cruise control can also benefit fuel economy because the vehicle uses less fuel when traveling steadily. 

In newer cars, you might be able to find adaptive cruise control , which is a smart technology. Adaptive cruise control allows you to travel at a predetermined speed, but it also helps to maintain a safe distance from the vehicles in front of you with the help of sensors. With conventional cruise control, you need to take over when the car in front of you slows down, but that’s not the case with adaptive cruise control. 

There are also vehicles nowadays with not only cruise control, but fully self-driving vehicles . We will most likely see much more of this in the future.

Cruise Control Repair Cost

The cost to repair your cruise control system depends on what caused it to fail. If you need to replace a cruise control or brake switch, you might spend between $125 and $350, including parts and labor. However, the cost to change a fuse is only a few dollars and you can perform the replacement yourself in just a matter of seconds. 

On the other hand, when something major fails, such as the actuator, you could be looking at a much higher repair bill. In some vehicles, the cost to replace a cruise control actuator can cost more than $700. These costs rise if you drive a luxury vehicle or one that is difficult to get parts for. 

It might not seem immediately important for you to fix the broken cruise control, but this defective system can affect other performance aspects. You could start to notice issues with acceleration or have trouble with the speedometer. To play it safe, it’s always best to have the cruise control repaired as soon as you notice a problem.

Is there a fuse for the cruise control?

Yes. If the cruise control is installed from the factory, you should check your car’s owner’s manual for the fuse location. If it’s an aftermarket cruise control, you’ll need to follow the wires to find the fuse.

Does the brake switch affect the cruise control system?

Yes. The brake switch affects the cruise control system. The brake switch sends a signal to the cruise control system to let it know when the brakes are being applied for the engine to know when it should stop accelerating.

Will the cruise control work if the check engine light is on?

The cruise control function will be disabled when the check engine light is on in most car models, even if the cause of the check engine light is not the cruise control itself. This is mainly due to safety reasons.

Can a vacuum leak affect cruise control?

Older vehicles use vacuum to control the throttle for the cruise control, and in this case a vacuum leak can heavily affect the cruise control. However, modern cruise controls are fully electric and in most cases will not be affected by a vacuum leak if the check engine light is not illuminated.

Although many people may think that the cruise control system is unimportant and not worth spending money to repair, the problem can be caused by a faulty part that will affect the engine’s performance or durability. Therefore, it is best not to ignore the problem if your cruise control is not working without first diagnosing the car properly.

If your cruise control still isn’t working after trying all the tips in this article, it’s probably time to take it in for a professional opinion from a mechanic. It may be a more serious problem that requires replacement parts or repairs. In the meantime, drive safe and enjoy the open road!

Learn more:

  • Brake Lights Not Working But Tail Lights Are? (How to Fix)
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  • Brake Lights Stay On? (5 Causes & How to Fix it)

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Cruise control not working

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Adaptive Cruise Control (ACC)

Adaptive Cruise Control helps your Volvo maintain a set speed or time interval in relation to the vehicle ahead.  This feature utilizes a camera as well as a radar sensor to detect slower moving vehicles ahead of you and automatically adjusts your Volvo's speed.  Once you are no longer behind the vehicle you will speed back up to your preset speed.   To activate the function, you must be driving at speeds 9 mph (15 km/h) or higher, the seatbelt needs to be fastened, and the doors need to be closed.  

To activate Adaptive Cruise Control:

  • Press the ACC button in the middle of the key pad on the left hand side of the steering wheel to put it in standby mode
  • Scroll to ACC using the arrow keys
  • a brief press changes the speed by increments of 5 mph, a long press will change the speed increment to 1 mph

To switch between Adaptive Cruise Control and standard Cruise Control simply swipe the Sensus screen from left to right to show the Vehicle Functions screen and tap the Cruise Control button. Note : Manual Cruise Control is only active at speeds above 20mph (30km/h).

Note : This system is designed to be a supplementary driving aid.  It is not intended to replace the driver's attention and judgment.  Adaptive Cruise Control cannot cover all driving situations and traffic, weather and road conditions.  ACC is not a collision avoidance system!  It does not sense pedestrians, animals, bicycles, or motorcycles.  You, as the driver, are always responsible for braking the vehicle.  

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  1. 6 Reasons Why Cruise Control is Not Working

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  2. Cruise Control Not Working? 9 Potential Causes

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  3. Cruise Control Not Working? Check Out All The Possible Reasons!

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  5. How To Use Your Volvo Cruise Control

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  6. I have a '99 Volvo VNL 780 w/ Cummins N14 Plus. My issue is the cruise control does not work

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COMMENTS

  1. Cruise Control not working? Try this!

    It's called a "brake pedal position sensor" and any shop (especially dealerships!) would love it if you came in and let them charge you $200 to replace one of these. Go to junkyard, spend $10-$15 and then come home and follow these instructions. Should take 5-10min in your garage. No special tools required.

  2. Volvo vnl cruise control not working

    Volvo vnl cruise control not working Discussion in 'Volvo Forum' started by goranvolvo, Mar 7, 2013. Page 1 ... cruise will work when the truck is parked,will not work when in motion

  3. Volvo 780 Cruise control is not working Inspection Costs

    1988 Volvo 780 V6-2.8L: Service type Cruise control is not working Inspection: Estimate $114.99: Shop/Dealer Price $124.99 - $132.49: 1990 Volvo 780 L4-2.3L Turbo: Service type Cruise control is not working Inspection: Estimate $94.99: Shop/Dealer Price $105.01 - $112.52: 1989 Volvo 780 V6-2.8L: Service type Cruise control is not working ...

  4. Cruise Control Not working

    My 2000 S70 the cruise control is not working. Does it have a separate fuse or relay causing this issue. Duckpa. ... Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine. ... 740, 760, 780, Bertone, 940, 960, V90, S90 ...

  5. Cruise control not working

    700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 cars: Information: VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. ... Cruise control not working. Views : 703. Replies : 12 Users Viewing This Thread : Page 1 of 2: 1: 2 > Thread Tools: Display ...

  6. 850 Cruise control not working

    850 Cruise control not working. I am working my way through the various threads on checking yet another thing the PO forgot to mention didn't work. I watched Roberts helpful video on the cruise system, but need help to identify how to check the pump under the battery tray is actually running. Took a while to figure out the relay is the large ...

  7. Volvo VNL780 Cruse Control, Idle override

    There was a limit switch on the clutch pedal and somehow it popped around to the back side of the clutch pedal; probably from getting in/out of the truck making deliveries. I'm not sure if Volvo has the same thing but that limit switch was there to 1. disengage the clutch and 2. disengage the cruise control (or in your case the idle override).

  8. 2006 Volvo 780 surging while using Cruise Control

    Just the output, seems as though things are working well currently. I will likely not mess with the input if things continue to work well. Good plan. Quote; 2006 Volvo 780 "Hoss" Volvo D12, 465hp, 1650 ft/lbs tq., ultrashift ... 2006 Volvo 780 surging while using Cruise Control Theme . Default . 4.2 (Default)

  9. 1990 Volvo 780 Cruise Control Not Working

    1990 Volvo 780 Cruise Control Not Working? RepairPal will help you figure out whether it's your Control Module, Sensor, Throttle, or something else. 1990 Volvo 780 Cruise Control Not Working

  10. I have a 99 Volvo VNL 780 w/ Cummins N14 Plus. My issue is…

    Cruise control does not work. 1b. Cruise control switch does not increase rpm at idle. FYI a recap so far: 1. Replaced clutch pedal micro switch 2. Replaced clutch pedal spring 3. Replaced vss 4. Continuity check across circuits from cruise control switch is fine 5. Engine brakes are functioning 6. Idle/Diag. button works raising or lowering ...

  11. Cruise Control on Volvo 700, 900 and 90 Series

    Install the brake switch, and clutch switch if manual transmission. Remove the metal clip and slide the switch into the hole provided. Install the retaining clip. Check the adjustment of the switch (es) with an electrical meter. I like to just tap the brake pedal and have the cruise control disengage.

  12. Cruise control just stopped working

    When cruise control didn't work for me it was because the brake position sensor mounted to the brake booster wasn't securely connected. The system saw that part of the stability system wasn't responding and shut cruise control down. ... Search "volvo installation instructions xc90 cruise control" on the web and a couple of PDF links will pop up ...

  13. Volvo VNL 780 ABS & TCS Lights: Q&A on Reset, Sensor Location

    Business management. Volvo mechanic. Triage Tech/Shop Foreman. Associates. Mechanic. Associate Degree. I have 2015 Volvo vnl 780. The ABS and TCS lights on and cruise control not working. Its not accelerate and decelerate i - Answered by a verified Volvo Mechanic.

  14. Cruise Control Stopped working

    This may work. My mechanic did this on my 94 945Ti when the cruise stopped working. Take the hose off the vacuum on cruise control module and use vacuum suction on the hose. It seemed to reset the module. Release pressure then hook it back up. I don't know the schematic of our R but it may be similar unless ours is electronic then all bets ...

  15. Cruise Control Problem

    Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine. 1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT 1997 - 2000 S70, S70 AWD 1997 - 2000 V70, V70 AWD 1997 - 2000 V70-XC 1997 - 2004 C70

  16. Volvo vnl cruise control not working

    After 1998 Volvo use VECU to controll engine (not with N14 and early Series 60). So no difference what engine you have, all switches in cab are connected to VECU Pablo-UA, Mar 8, 2013. ... Funny thing, cruise control working only when the truck reverse, stop work in forward... ah fai, Mar 13, 2013. ah fai, Mar 13, 2013

  17. Cruise control not working

    No it won't work. Failure of the clutch position sensor is a common fault. To test, start car in neutral with clutch pedal down, set cruise. If the word cruise on the dash display illuminates and then goes out when the clutch pedal is released, it's almost certain the sensor is the problem. Easy to replace.

  18. 5 Reasons Why Your Cruise Control Stopped Working

    It can also be caused by issues with the throttle control system or the ABS. In older cruise control systems, it can be caused by a broken vacuum line. Here is a more detailed list of the possible reasons your cruise control is not working: 1. Blown Fuse. All electrical systems in the vehicle are controlled by fuses.

  19. Cruise Control

    Press the Cruise Control button on the left steering wheel key pad (located in the center). Once it is activated the symbol will change from gray to white. Press the "+" or "-" button on the same keypad to set your desired speed. A quick press will change the speed at 5 mph intervals or you can press and hold the button to change the speed at 1 ...

  20. Cruise control not working

    The two most common failure points are the vacuum line to the cruise control pump under the battery tray, and the brake switch as stated. Other than that, sometimes the turn signal lever goes bad or the cruise control relay, but those would be last on my list to troubleshoot. '98 S70 T5. 2016 Chevy Cruze Premier.

  21. Volvo S80 Cruise Control Not Working

    Volvo S80. The most common reasons a Volvo S80 cruise control isn't working are failed control module, sensor or switch issues, or throttle actuation problems. 0 %. 10 % of the time it's the.

  22. Adaptive Cruise Control (ACC)

    To activate Adaptive Cruise Control: Press the ACC button in the middle of the key pad on the left hand side of the steering wheel to put it in standby mode. Scroll to ACC using the arrow keys. Use the "+" or "-" to adjust the speed. a brief press changes the speed by increments of 5 mph, a long press will change the speed increment to 1 mph.