1995 SLS, cruise works fine, but whenever you turn the engine off a loud clacking comes from under the hood. Its the cruise control unit trying to do something, I dont know what. But you can see it jerking and releasing the left cable (as you look at it from the drivers side fender). Whats up with that?! Its very loud and cant be good for the cruise control. Any ideas?
Keith

 

Idle/tps may not be learned causing ECM to cycle ISC trying to decide what throttle position should be at start up. Check for codes and post if present, clear codes, restart car, and recheck then post what if any come back.

 

You may have to change your ISC motor.
Thats the little black box that makes the ratcheting sound that you hear.
If thats where the sound is coming from.

Pop the hood and watch and listen. If thats the case then it has nothing to do with any learn. Either way...Learn has nothing to do with it. If the ISC is making a ratcheting sound then its on its way out and will need to be changed.

The ISC should not make a ratcheting sound.

 

The ISC is the cause. Usually because its misadjusted, not going out. Need to verify the ISC is adjusted by the factory service manual. If adjusted to spec then the "nose" switch within it is faulty. If the ISC is proven faulty, the new one must also be adjusted when installed.

 

ISC. That one threw me. I finally figured out it was the idle speed control. Acronyms... caused me some initial problems...
Anyway, the click or clack went away by itself. I don't know why it started, although the car was at the body shop for about a week, just sitting. Very odd.
Keith

 

Not really, ECM lost it's memory and now has re-learned it.