P1651 BUICK, CADILLAC, CHEVROLET, GMC, PONTIAC, SATURN: FAN 1 RELAY CONTROL CIRCUIT
POST UPDATED IN June, 2023
P1651 BUICK, CADILLAC, CHEVROLET, GMC, PONTIAC, SATURN: FAN 1 RELAY CONTROL CIRCUIT
The vast majority of vehicles employ fans with electric motors so that the temperature of the car’s engine is maintained at the proper levels to achieve good engine performance.
ODMs (Output Driver Modules) are used by the Powertrain Control Module (PCM) to activate or turn on various current-driven devices, which are necessary to control many engines and transaxle functions. Each ODM can control up to 7 separate outputs by applying ground to the device that the PCM activates.
Unlike the QDMs (Quad Driver Modules) previously employed, the ODMs have the capability to diagnose each output circuit individually. The P1651 OBDII fault code is set when an improper voltage level is found on the ODM B output that controls the fan 1 relay.
The factors by which the P1651 OBD2 diagnostic code is stored are:
The steps to follow to correct the DTC P1651 OBDII code are: