I placed my truck in park and the engine light came on & it wouldn't move. Got a message stating "engine power reduced". I waited 5mins then I was able to drive it. Took to Auto Zone and had a scanner placed on it and got code P0641.
Had the same problem 3 weeks ago & I replaced the Throttle Body, Engine Oil Sensor & Accelerator Pedal Position Sensor. Now I'm having the same problem "AGAIN".....PLEASE help!!

 

its either a bad wire or ECM

 

Do u kno which wires or I have to go fishing?

 

It is the ECM, covered by Federal Emissions Warranty of "8 year / 80,000 mile", so if your vehicle is less than 8 year old and under 80,000 miles take it to a GM Dealership and tell them about the problem and mention the warranty. Cost for replacement ECM AND any diagnostic work is covered, cost is ZERO to you.