P1682 BUICK, CADILLAC, CHEVROLET, GMC, HUMMER, PONTIAC, SATURN: IGNITION 1 SWITCH CIRCUIT 2
POST UPDATED IN February, 2023
P1682 BUICK, CADILLAC, CHEVROLET, GMC, HUMMER, PONTIAC, SATURN: IGNITION 1 SWITCH CIRCUIT 2
The ECM (Engine Control Module) has a supply of 2 ignition circuits. The first circuit is provided by the powertrain relay via a fuse. In this circuit 1, power is delivered to all internal circuits of the ECM that are related to the performance of the TAC (Throttle Actuator Control). The second ignition circuit 1 is provided by a crank/operating relay via a fuse and is used to provide power to the internal circuits of the ECM.
When the fault code P1682 OBDII is set, it is because the ECM has found a difference in the voltage levels of both main power inputs to the ECM. An additional code to this one can be stored by referring to the voltage that is different from the other.
The reasons for storing the diagnostic code P1682 OBD2 are:
The steps to solve the DTC code P1682 OBDII are the following: