I'm not sure if this is the proper section to ask this question, but here it is. When cruising in Drive at hiway speed, I put the automatic trans gear selector into O/D. Within one minute the "check engine" light comes on, but there is no change in vehicle operation and the light remains on until I restart the engine. Is this cause for concern?

 

First, you'll need to pull up the trouble code to determine where to start trouble shooting.

Is the CEL off when you shut down and restart?

http://www.troublecodes.net/GM/

 

The CEL is off when I shut down. Naturally, it comes on when I restart.

 

Paulo57509,
I was unclear in my reply. CEL goes off when engine is shut down, then comes on momentatily on restart to show bulb is operational, then goes off when engine starts and remains off until O/D is engaged again.

 

Best thing to do at this point is pull the trouble code per the link in my previous post. This will give you a place to start your diagnosis.

 

sounds like a code 32 to me.

 

Crazy EGR Code 32.......