cruise control not working properly

john.bosyj@gmail.com

Active member
Joined
Nov 23, 2016
Location
Canada
TDI
jetta
Ever since I had my Jetta MK4 converted to a manual transmission, the cruise control does not work properly. 1st thing in the morning as I am heading down the highway, the cruise control works perfectly fine. After about 30 minutes, the "reset +" stops working. I can press that button a million times and it will not work. After about 40 minute the cruise control suddenly stops working. Again, I can press the "set -" a millions times and it will not turn back on. When I drive home in the evening, the cruise control is working again and then stops working just like in the morning. Any ideas what could be the problem?
 

robm2

Active member
Joined
Jul 21, 2017
Location
Terrace, BC, Canada
TDI
2003 Jetta Wagon
Could it be temperature related? The buttons perhaps stop working as the interior of the car warms up? Does the "cruise" indicator on the dashboard go out when it quits?

My "cancel" button has stopped working completely. Sometimes, the CC will not work at all, and I find I have to shut the car down to get it to function. Usually, that does the trick.

Have you tried shutting the car off after the CC stops completely, to see if that fixes it?
 

Vince Waldon

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Joined
Apr 25, 2009
Location
Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
It can also do that if it sees a series of confusing signals from the two sides of the brake switch.

Quickest thing would be to track down someone with VCDS: you'll then be able to read the operation of all three sets of contacts and at least rule out the easy stuff.

In the absence of that... if all this started *after* the conversion... the clutch switch is the newest player on the field so... :) :)
 

john.bosyj@gmail.com

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Joined
Nov 23, 2016
Location
Canada
TDI
jetta
Maybe I'll try driving to work with the heat off to see it it makes a difference The light on the dash stays on when it stops working. I tried shutting off the car to see it it will work normally and it doesn't.

There have been times that I could drive without ever touching the brake pedal or clutch and the CC still shuts down after 30-40 minutes. Could it still be the clutch switch or brake switch that can cause two separate issues with the CC- one being the reset + and the other being the set-. When I had the conversion done, they did need to do something with the ECU. I'm wondering if that is the problem. Thanks
 

wonneber

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Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
Long shot but check fuses 5, 13, and 43
Check for clean and tight connections.
I've read some cheap fuses crack internally and look OK. Maybe open circuit when it heats up?
 

john.bosyj@gmail.com

Active member
Joined
Nov 23, 2016
Location
Canada
TDI
jetta
So I checked fuse 5,14,43 and all are ok. I also drove to work with the heat turned down and still the cruise control stopped working. I did however notice something. When the cruise control stops working, the horn also stops working. I have a multifunction steering wheel with the cruise and the radio controls mounted on the steering wheel. The radio controls also stop working when the cruise control stops working. Again, this all happens after driving about 30-40 minutes down the highway. Any suggestions?
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Do a scan with VCDS to look for DTCs. Scan every system that is supported. Sometimes codes will be where you'd not think they might be and not result in a CEL or flashing GP light.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
When the cruise control stops working, the horn also stops working. I have a multifunction steering wheel with the cruise and the radio controls mounted on the steering wheel. The radio controls also stop working when the cruise control stops working.
Maybe scan for codes when the items aren't working.

When the horn stops working check if fuse 40 (20 amps) has power.

Also check if any of the fuses above the battery have no power or have a voltage drop at the clamps on the wires.
 

john.bosyj@gmail.com

Active member
Joined
Nov 23, 2016
Location
Canada
TDI
jetta
Solved! Turns out that when the relay was installed for the transmission swap, the adjacent relay 451 became slightly dislodged. The horn, cruise control and radio controls on the multifunction steering wheel connect to relay 451. I pushed it in all the way and everything works properly. Thanks
 
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