Hi folks,

This is actually a question about a Buick Rendezvous, but fan support for that model is poor, so I'm hoping someone here might be able to help me.

I've been called to troubleshoot a 2005 Buick Rendezvous that is suffering unintended acceleration.  The family friend reports that sometimes when breaking the engine speeds up, and the car attempts to push through its brakes.  It happens at random, and isn't intentionally repeatable.

Last night, she said that it happened for the first time while cruising.

Internet searching is a dead end for me.  Off the top of my head, I'm thinking TPS, IAC, or throttle body vacuum leak, as culprit.  I'd considered the possibility of a brake booster vacuum leak, but that wouldn't explain accelerating while cruising.

Anyone have any thoughts or suggestions? I can't find any report of this online.  If anything, it's usually the opposite... having trouble accelerating.

Thanks,
Jim

Mine would do this but also it wouldn't shift properly while accelerating. I replaced the TPS and it stopped.