Code 75, 76 Or 77, EGR Solenoid Error: Notes

The PCM performs an EGR diagnostic check to monitor the flow of exhaust gases through the 3 EGR solenoids. When the vehicle is under deceleration, the EGR valves are normally closed. The PCM then opens each valve in succession (while keeping previous valves open) and manifold vacuum is monitored for a calculated MAP increase associated with each valve's application. Should the expected response of manifold vacuum not be seen by the PCM, a Code 75 (solenoid No.1), 76 (solenoid No. 2) or 77 (solenoid No. 3) will set.

1. This test determines if there is power to the EGR valve.
2. This test will determine if there is an open circuit in the EGR wiring or if the EGR valve is at fault.
3. This test will determine if there is a short to ground in the solenoid drive circuits or if the PCM is at fault.