Cruise Control not working

[wild giles]

Trying to figure out why I lost cruise control on my Jetta TDI PD mk iv with Triptronic transmission

I have used Ross Tech Vagcom to trouble shoot, all the controls show as working in vagcom and all the brake lights and whatnot work as should, brake switch works, bought a new one in case it was that. The only thing amiss is that the VSS shows as 0km/h in the cruise control measuring block, speedometer shows correct speed, no fault codes for ABS or transmission. Only fault is implausible signal form o2 sensor once in while when engine braking after 90 min on highways, guessing o2 sensor needs cleaning.

 

[snakeye]

Try activating the cruise control while signaling left and right.

 

[Tdipwr11]

That's seems like a good tip above. I had my cruise not working before and you start with the brake switch replacement. If it signals the brakes are on, it won't activate the cruise. They are cheap OEM to replace like under $10cdn. If that doesn't work I'd say it's the stick going into the column. I've had to have that done to fix the cruise

 

[Seatman]

For me it was the clutch switch not set right, had to pull the plunger out then let the clutch pedal up to set it to the correct place then my cruise worked. That was on a mk4 golf

 

[Tdipwr11]

Interesting

 

[wild giles]

Thanks for are your inputs, I have checked the stalk the control for turning on Cruise Control, setting speed are in the steering wheel. All that works according to Vag cam check for signals to the computer, checked 3 or 4 times, lol. Tried the left and right turn signal thing, no difference, most likely due to speed setting buttons are on the steering wheel anyhow. Cruise light turns on and off in dash board. Not sure about clutch switch as this is an automatic trans with Jetco 0A9. I'm leaning more to a wheel speed sensor bing slightly off somewhere, but who knows when they look the same when driving with Vag com abs wheel speed monitoring up on my laptop.

 

[oilhammer]

The cruise control is all resident in the Engine Controller on that car. The ABS is a separate entity, with its own separate inputs.

Are there any DTCs in the Transmission controller?

 

[wild giles]

I do have a fault code for implausible transmission Temp sensor signal, I assume that the coolant temp sensor reads a bit high (shows 95 deg C when car warms up in VAGCOM) and doesn't match transmission temp. No other fault codes.

 

[oilhammer]

I wouldn't think the ATF temp sensor would lock out cruise control.

But read through this to be sure:

http://www.volkspage.net/technik/ssp/ssp/SSP_232.pdf

 

[BobnOH]

Outlier- Some folks have reported MAF malfunction knocks out the cruise.

 

[wonneber]

Outlier- Some folks have reported MAF malfunction knocks out the cruise.

Yes
My 03 was having over boost problems w/o the CEL going on.
On the high way cruse would cut off and not work again until after a restart.
Once I solved the boost problem cruise was OK again.

Have you scanned for codes after the cruise goes out and before turning the engine off?

 

[wild giles]

Replaced MAF, quite weird that the new MAF caused loss of power and turbo until the engine was reset by disconnecting battery. Boost works fine, but I did get a vehicle speed sensor fault today. The crankshaft speed sensor was replaced two years ago, everything else. Going to have a look at the wiring and grounds between speed sensors and ECU net I guess, this is quite a head scratcher. Still no cruise control.

 

[Seatman]

Replaced MAF, quite weird that the new MAF caused loss of power and turbo until the engine was reset by disconnecting battery. Boost works fine, but I did get a vehicle speed sensor fault today. The crankshaft speed sensor was replaced two years ago, everything else. Going to have a look at the wiring and grounds between speed sensors and ECU net I guess, this is quite a head scratcher. Still no cruise control.

A quick scan will tell you which corner is at fault and whether it's mechanical or electrical.

 

[oilhammer]

See post #7: Engine (and thus the cruise control) doesn't use nor care about the ABS wheel speed sensors on that car.

 

[wild giles]

I’ll be looking into wiring from the VSS from TSM to the ECU and the grounds. Maybe TSM or ECU is fried in some way.

 

[oilhammer]

Pretty sure (but not 100%) that the 09A uses its own dedicated speed signal off the transmission itself, and the VSS is just a signal sent straight to the Instrument cluster (the 01M does take a signal from that, however). Then the Engine gets the signal from the Instruments across the CAN lines.

 

[Seatman]

See post #7: Engine (and thus the cruise control) doesn't use nor care about the ABS wheel speed sensors on that car.

Yeh I misread and assumed wheel speed instead of vehicle speed. So far my comments on this thread have been perfect! Clutch switch on an auto, abs instead of vehicle lol

 

[wild giles]

Still have not figured what's wrong with criuse contro. Engine and Transmission shift smoothly, Instrument cluster shows speed. Still shows 0km/hr for VSS in the cruise control measuring block in VAG COM. Cleaned the ground wires near the ECU.

 

[Powder Hound]

I am watching this thread, having the same problem. Mine is a new-to-me Y2K Jetta, 5-sp, 234k miles. I have a 'soft' limp mode coming from time to time. Soft in that the loss of power is low. The DTC (didn't write the code down) says mainly negative deviation on boost, and I thought a hose had a cut or there was a loose joint, but that is not apparent.

I have no cruise engagement at all.

Group 6 data items are OK when testing in static (engine not running). No speed to check that variable, obviously, but the other items work as far as brake and clutch switches, and the control stalk buttons.

The MAF does not appear to change much at all when revving, and the MAP isn't interested in changing either. I need to check the MAF, MAP, N75, vacuum (leaks and source), and vacuum operation of the turbo vanes (does the vacuum can hold vacuum and does it activate the vanes correctly). So, there's work for me to do.

Cheers,

PH

 

[wild giles]

I think I replaced every sensor a least once except the ones buried in the auto transmission. Replaced turbo at around 300K Miles, Turbo actuator has been replaced 3 times since then, only get about three years before they rust out. All of the vacuum lines replaced. Tandem Fuel/air pump replaced, leaking diesel(not good) and oil before replacement, one of my first replacement jobs on this car. Fuel injector loom replaced( brittle + leaked oil). Steering rack and lines went out around 360K miles. Replaced EGR Valve, leaking gas and oil soot. Brake booster replaced, a bit hair razing when your brakes don't slow down fast enough.

 

[Cleenlivin]

I think you already cleaned your ground wires but did you also check the ones beneath the battery tray? When I bought a used 04’ from New Jersey I had problems with the cruise and engine idle surging. I checked the grounds beneath the battery tray, cleaned them and installed new body grounding posts. It helped get rid of the idle surging and my cruise started working.

 

[DuraBioPwr]

Its was the clock spring on mine was why the cruise no worky. They are expensive too! It may not show vehicle speed unless the cruise is 'on' and it cant be turned on if the clock spring is broke (wires anyways). I have stalk controls on mine too, they do nothing its all through the steering wheel. Kind of weird why it even has the controls on the stalk. Somebody must have replaced the stalk at some point with a different version on mine.

 

[wild giles]

Cleaned the ground wires under the battery, still no cruise control, I’ve checked the switch controls using vcds all works there. Something still telling cruise control block vss to be 0km/h.

 

[Seatman]

Bit of a long shot but what about entering the activation code in the ecu, think it's 11463, select engine, login, enter that number and hit do it.

Maybe something has gotten lost somewhere. Weird things happen when it comes to electronics and cars and it's easy to try.

 

[AndyBees]

Powder Hound, revving the engine will not change data much at all. Playing around with VCDS, I've noticed very little difference with the ALH in my Vanagon which runs just fine.

I agree with Seatman.. But, write down existing long-in data/codes before entering any changes in case you want or need to go back with the OE data.

 

[wild giles]

Yeah I did the 11463 thing a couple of months ago, didn't do anything, I think my next cheapest thing I could do is replace all the external wires that lead from the vss inside the tiptronic transmission to TSM and the ECM. I really hope its not the internal VSS that's gone half bad or something.

 

[wild giles]

Update, had a look at the instrument Cluster connectors, The Blue/left hand plug one was not all the way seated in place, thought this might be the problem after all, but alas still the same problems with cruise control.

 

[wild giles]

Going to check Wiring from Pin 3 Blue pigtail Instrument to either pin 20 or 54 of the 121 pin plug on the ECU, if that doesn't solve Cruise control then I'm going to get a new ECU. Any body else verified that Cruise control pin 20 pr 54 to ECU should be getting VSS from Instrument cluster?