Hello,

Can anyone tell me exactly how the cruise control engages the throttle body? I understand about the electrical operation of the switches etc. but when all that takes place, where is the signal going that it causes the throttle to continue to keep the car at the speed that has been set? There are a number of connections to the throttle body, apart from the TPS sensor, I am not able to find what these are or what they do. Any information that could be put forth would be greatly appreciated.
Best, Dave Warner
2000 Red VDP
Atlanta GA

 

The throttle body is operated by a step motor under control of the ECM for both throttle and obviously cruise. Operation is contained in software plus a few mechanical parts.

Sorta hard to describe the software.

A number of the Atlanta area forum members are gathering in Kennesaw for a Cars-n-Pizza this Saturday at 1pm.

Rosaria's Italian Restaurant
3103 Cobb Parkway Northwest #105, Kennesaw, GA 30152

 

Hello,
Thanks a bunch for that explanation. It makes sense and about an hour after i posted the message I realized that it has to be the motor. So any issues with the cruise must be related to an electrical problem since the motor is the butterfly actuator.
Now it's on to checking the wiring for a switch or connection problem.
Sorry to miss the fun Saturday. I have another plan for that day.

Best, Dave

 

What is your CC doing or not doing?

Disabling CC is a common first item associated with many other problems. Do you have any OBD codes set?

The cruse switch on the center console has been reported as a problem. Mine needs some exercise occasionally. Next step is to pull the switch and spray the contacts with some contact cleaner.

 

I do not have any other codes. I don't use it much but about a year ago I turned the switch on and i could not get anything to function beyond the LED on the switch lit up. No response from the steering wheel controls. I'll try the switch cleaning with CRC fluid. Ill let you know if it changes anything...Thanks for replying! Dave Warner

 

It may be that the contacts in the brake switch are not closing. There are two sets of contacts there, one for brake lights, the other for cruise control.

 

I checked that already. I will next meter out the pins in the grey cruise control connector by the steering column to see if the switches work. I have the JTS schematics so will follow the trail to the end point.
Thanks much. Will let you know if i find the problem. Will have to wait until next week earliest.