S5 Electronic Cruise Control Repair
 

The following guide describes the process for repairing an S5 cruise control computer unit that has a continuous short regardless of the condition of the sensors, controls, and motor. This is likely a rare fix for you guys, but it happened to me, so it can happen so someone else. Our cars are 30 years old. We need to know how to fix these computers because eventually spares will be impossible to find. Also included is the list of electrolytic capacitors required for replacement. Let me know what you guys think.

Matt

Good write up

Funny thing, i thought this is what happened to my 89 vert but it turned out i forgot to check if the cable was even hooked up the the TB lol

Turns out the previous owner forgot to put it back on after a repair and viola! ended up working.

I searched for 30 minutes before I posted this and didn't find that. Ugh.

That said, that's different from what mine is doing. I need to double check ALL of the pins, but they seemed correct on the computer, other than the voltage didn't go to 0 when I pressed the set button. Its good to know the computer is somewhat serviceable, though. At this point I'm grasping for straws because I really don't want to pull the steering wheel again to get at the cruise switch.

In my case, the motor driver chip failed and the cruise system just kept displaying that there was a short, no matter how many times I checked the switches and extra stuff.