I am very hopeful someone here with some experience on Caddy cruise controls can help me.. PLEASE!

'93 Eldorado ETC, 110k miles, 4.6L Northstar.
No error codes, except 8 out of 10 times when engaging cruise.

Cruise was working great until one -23 degree day.. It quit on a dry level section of road. Code set was P061. I followed all of the troubleshooting steps I could find in the service manuals.. Everything checked out fine. When cruise is engaged the friendly "Cruise Engaged" message appears on the dash, but no worky. Code P061 or sometimes P061 and P062 are set. I completely disassembled the servo assembly, tested both vent and vacuum solenoids, and reinstalled. Same problem. Out of sheer frustration I replaced the PCM. Same problem. I also ran a ground wire from the correct terminal of the servo assembly to a "known good" ground. Figured the ground was common ground (no pun intended) between the P061 and P062 codes.

I just disassembled and cleaned the switch on the brake pedal. Same problem.

All tests pass, set/coast/on/off/brake, etc, etc when testing the inputs (PI070, 83, 84, etc) :banghead:

I see some time ago there was a Thread here with a similar problem, and a new brake switch solved the problem. Could the problem be in the on/off switch on the column? Why the P061 code? What does the "feedback" circuit in the PCM look like and do?

I have some long trips comming up soon, and would greatly appreciate any input anyone may have.

Thanks in advance!

I had a similiar problem and the dealer had to replace the entire cruise control switch on the steering column. Never had a problem after that.