P1406 BUICK, CADILLAC, CHEVROLET, GMC: EGR VALVE PINTLE POSITION CIRCUIT
POST UPDATED IN June, 2023
P1406 BUICK, CADILLAC, CHEVROLET, GMC: EGR VALVE PINTLE POSITION CIRCUIT
The EGR (Exhaust Gas Recirculation) valve has a sensor that detects the position of the EGR valve shaft and then transmits that data to the Powertrain Control Module (PCM). The EGR position changes according to signal voltages ranging from 0.1 to 0.3. The PCM memorizes the valve signal voltage when the valve is closed after a vehicle activation. This value is used by the PCM as a reference and is compared to subsequent values of the closed position during each ignition activation.
The PCM often checks the EGR shaft position to verify that the EGR shaft position is within the parameters necessary for the best performance. If the EGR shaft position is +10% of the expected position, the P1406 OBD2 diagnostic code will be set.
Reasons why the OBDII DTC P1406 is set:
To troubleshoot the P1406 OBD2 fault code you must do the following: