2008 Chevrolet HHR-Reduced Power-Code P0641

This 2008 Chevrolet HHR came in with the complaint that the check engine light would come on, the reduced power message would display and the car would no longer accelerate. There was a code P0641 stored.

The code p0641 means that the 5 volt reference is outside of the 4.8 to 5.2 voltage range needed to keep the PCM happy.  In this case I observed a 5.5 volt reading in the 5 volt reference 1 data line under PCM-TAC live data.

A little bit of searching and I found this connector located under the passenger side rear of the truck. Just in front of the rear axle area. It is the pass through connector for the fuel pump assembly.

The customer was not able to afford a proper repair so I took an air hose and blew the water and corrosion out of all parts of the connectors. To my surprise they actually came quite clean. I lightly scrapped the terminals down and installed some electrical grease in the  connectors.

This took care of the problem but I explained to the customer that the problem will likely return one day and more work will be needed to repair it correctly.

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