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P0401 Diagnostic Trouble Code Discussion for October 2020

Insufficient EGR Flow Detected


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Trouble Ticket Help Requests for DTC P0401
Help Request Posted
2011 GMC Sierra 3500 HD SLE 6.6L MIL Lamp on VIN: 1GD523CL2B
P0401: Exhaust Gas Recirculation EGR Flow Insufficient. I have codes listed, but most of all I need your help on the outside air temperature sensor (OAT) before I start on the other codes. The MDI shows the PID for the outside air temperature at -40 degrees when in engine data. I checked the sensor resistance/t...
October 28, 2020