Cruise Control kicks off?

[Lance CA]

Has anyone had problems with thier cruise control kicking off? Mine seems to do it for no given reason while cruising the highway.
Thanks in advance.

[joshremus]

I've been experiencing the same issue, did you ever find the culprit? The dealer can't make it happen, but it still happens often to me.

[bearcatdon]

Shot in the dark here but maybe a vacuum leak.

[gapboi210]

I don't think that there are vacuum lines on the cruise for the Malibu's I believe that they are all electronic.

[bearcatdon]

I just checked my wiring diagrams and your correct. Where is that module located?

[gapboi210]

It is the box that sits on the left side of the motor by the pulleys. It it held up there by a clip. The is a harness and a cable going to the throttle coming out of it.

[micosan]

My 2001 Malibu started having problems in Jan 2004. I noticed occasionally the RPM would jump 200-300 RPM at highway speed. This RPM increase was usually associated with bumps or vibrations from the road. As the months went by I notice when the cruise control was active the bumps or vibration would cause the cruise control to disengage. Sometimes the problem would be infrequent and other time the cruise control would disengage at the slightest road vibration. I took it to the dealer three times. The 1st time they said the problem could not be replicated. The 2nd time I asked for the transmission tech to ride with me and he saw the RPM jumped. My original fear was something in the transmission was malfunctioning. The warranty repair from the dealer said the cruise control disconnect switch attached to the brake pedal was cleaned and adjusted. After leaving the dealership the 2nd time the cruise control disengaged before I had driven 5 miles. I returned to the dealership asking for the cruise control disconnect switch to be replaced. They said the car was working normally. Needless to say my problem continued and I was left to fix it myself.

Test – I removed driver air duct panel under the steering wheel to access brake and cruise control disconnect plunger switches. I started the engine so the brake pedal could be depressed easily to aid in removal of the air duct panel. I found a lightly traveled road and set the cruise at 30mph and then tapped on the cruise control disconnect switch with my finger to simulate road vibration. The cruise control disengaged confirming my diagnosis. The cruise control disconnect switch is the one on the left looking forward from the driver seat. The other is the brake switch which activates the brake lights.

It was a Sunday so I couldn’t get a replacement switch. The switch is serviceable so I opened the switch and bent the contacts so the connection wouldn’t break with the slightest vibration.

I speculate the tech only checked to see if the switch was contacting and breaking when the plunger was moved back and forth. The problem was the contacts themselves were bouncing under driving conditions and so randomly that the tech couldn’t replicate the issue.

I hope this helps you in finding your problem or at least eliminating this as a source of a problem.

[barefootboatnik]

What a great writeup that was... solved my problem EXACTLY! Thanks!!