Tach-trac Control Problems

[wgabert]

I am a reader of this forum but do not post frequently. I have learned plenty from all the GM techs.

 

Here is one I am having trouble with. 2001 pontiac gran prix gt. this issue has been present for about a year. it is slowly increasing in fequency. after starting and running down the road for anywhere from 10minutes to an hour the engine will stutter for a split second. this always happens when running in OD at speed (as far as I can tell). The tach will quit and the trac control light will illuminate. The car performs as well as before. If I pull over or just go to my next stop and turn off the ignition and fire it up all is well for a while again. Any Ideas? on where to start No dtc showed on the scanner

 

 

Thanks

Warren

[bobcat5544]

Check the wire harness by the A/C accumulator on the driver side front under the air cleaner box. Look at the wire harness that runs around the A/C accumulator and see if it has been rubbed open. It is the most common problem that causes all kinds of differnt problems.