How to trouble shoot flakey cruise control

kyser_soze

Member
Joined
Oct 5, 2013
Location
Kansas City
TDI
2000 New Beetle
Still works after all these years!

I just ran into this EXACT same problem. I had all the replacement parts and the tools to replace but I decided to try the 'Wingnut method' as a last chance try, and it WORKED!
 

Prairie Chicken

Veteran Member
Joined
Jan 28, 2014
Location
Northern IL
TDI
05 Jetta, 04 Jetta
Great post - I have been without CC for way too long and the contact cleaner hadn't helped... was procrastinating because I though I'd have to pull the stalk. Will be fixing it for a penny on my clutch pedal tomorrow.

Finally disabled that annoying seat belt chime also. Yes, I always wear my belt, but like to start it up right away then get organized (adjust seat/mirror/radio from wife driving, deal with bag, drink, shades, phone...)and now don't have to deal with the "dings" while I do so.
 

Mike Morriss

Well-known member
Joined
Dec 25, 2001
Location
Ponca City, Oklahoma
TDI
99 New Beetle, 91 Vanagon TDI conversion, 05 New Beetle, 2014 Jetta Sportwagen
My cruise control did not work for about a year and I could never figure out what it was. I ran the vag-com on it and kept replacing the clutch and brake switch only to find out that the LED taillights i installed had a small capacitor on them and as soon as it was charged the lights would always stay on slightly. It was not noticable throught the taillights but if you took them out and looked then u could tell they were on. So my LED taillights caused the cruise to not work.
The problem, at least on some models, is the system checks for voltage on the brake light circuit to be at or near zero V when cruise is supposed to be engaged. LED lights don't pull the voltage down enough. Simply install a resistor across either of the brake light wires to ground to fix this. I went to LED tail/brake lights because the sockets for those bulb would melt and deform badly if I was in traffic enough that I had to keep my foot on the brake pedal a while.
 

eb2143

Top Post Dawg
Joined
Dec 26, 2005
Location
Rhode Island
TDI
None
A few videos that may help

I'll add my story to this excellent troubleshooting thread (that I did not find initially). My car is a 2001 with original stalk and clutch switch. My car has long started without the clutch being depressed, which confused be, until I realized there are two clutch switches.

Symptoms:
  • intermittently for last 1-2 yrs, cruise control would not engage; failure to engage was occurring more frequently
  • was more likely to work when it was hot out; rarely worked in the winter unless the cabin had been heated for a couple hours on a long drive
  • the acceleration slider switch on the stalk was flaky (sometimes caused the cruise control to cut out when it should have increased speed), so I assumed the stalk just needed to be replaced and that my cruise issues were originating there

What I did:
  • replaced cruise control / turn signal stalk with no change; thankfully the change went very smoothly (before I had my 3-spoke steering wheel, I had tremendous difficulty removing the airbag from the 4-spoke OE wheel -- bag removal was super easy with the 3-spoke)
  • found this thread, started troubleshooting and it appeared everything checked out: I tested measuring block 6 three times and the new stalk, brake switch, brake lights, clutch switch, and #5 fuse were all fine

Finally, today, I caught the clutch switch stuck in the "depressed" state.

I made a couple videos because I had the time this rainy afternoon.
First video shows what Wingnut describes in post #1:
https://www.youtube.com/watch?v=IBOJc-URU_0

Second video is unlikely to be useful but may be of interest to a nerd who is curious how this switch failed:
https://www.youtube.com/watch?v=tq3OjkF2y10

Moral of the story:
  • don't blindly throw parts at a car when VCDS can help you
  • whenever you have a flaky electrical issue, it can require a lot of patience to replicate the problem
 

MagicMan

Member
Joined
Apr 20, 2012
Location
New York
TDI
Silver on Black 2002 VW Golf GLS TDI
Hey everyone!
My cruise light works, but cruise won't set.

I read through some of the beginning of this post on the cruise control diag with the vcds read outs.

I have a V-Checker 202 and went into engine electronics, measuring blocks, typed in 006 and I see the following with car on, cruise off, nothing pressed:

X1XX0XX0
XX100000

Cruise switch on:

X1XX0XX0
XX100011

Clutch pedal pressed while cruise switch on:

X1XX0XX0
XX100011
(No values changed. My guess is that the first row should be:
X0XX0XX0 when clutch isn't pressed, and then:
X1XX0XX0 when clutch is pressed?)

Brake pedal pressed while cruise switch on:

X1XX1XX1
XX110011

Set button pushed while cruise switch on:

X1XX0XX0
XX100111

Resume button pushed while cruise switch on:

X1XX0XX0
XX101011

My guess is that it thinks my clutch is pressed at all times? Which makes sense as to why it won't set cruise speed.

However... Why do I need to press the clutch to start the car? Doesn't that mean the switch works?

Thank you in advance!
-M
 

rmidgett

Well-known member
Joined
Feb 10, 2012
Location
Nashville
TDI
2001 Jetta GLS
I'd been without CC for a couple of years. By reading through this thread, I was able to troubleshoot the problem to the switch on the clutch pedal. My switch failed such that to the ECM it seemed the clutch pedal was always pressed down. The switch was open when it should have been closed by the clutch pedal in the up position. Rather than replace the switch, I jumpered across the two pin female connector that connects to the switch. A crimp style fork connector fits into the socket nicely, and the CC works again. Having VAGCOM to be able to see the data change was very helpful to repairing this issue.
 
Top