P2123, Reduced Engine Power
 

I'm not much of a computer guy so this might have been answered. I have been looking but nothing has fixed my problem yet.

I suspect it's a ground but I'm not sure how to verify.

2008 Silverado.

P2123, Reduced Engine Power. A buddy has the same truck. We switched acc. pedals, no joy. We switched throttles - both needed a good cleaning and a new seal couldn't hurt, no joy.

None of the connector wires seem loose, they don't pull to the touch.

The only ground I'm aware of is the braided wire from the rear engine to the firewall behind the driver's side door. Is there another ground location? I have the Haynes Repair manual, but unfortunately it doesn't mention it and the wiring diagrams are beyond my abilities. I do have a multi-meter but I'm not sure what I'm looking for on the throttle wiring cable.

Thanks for any help.