Door Locks: Description and Operation

DOOR LOCK DIAGNOSIS

See Mazda truck wiring diagrams.

Principles of Operation

Power Door Locks

NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).

The smart junction box (SJB) controls the power door locks and remote keyless entry (RKE) system. The lock and unlock operation is carried out by supplying ground to the SJB from either door lock control switch. The door lock actuators ground through the SJB. The door lock control switch locks and unlocks all doors by grounding the appropriate circuit to the SJB. The SJB then supplies power to the appropriate door lock actuator circuits to lock or unlock the doors.

RKE System
The RKE transmitter sends a signal that is received by the SJB. If the unlock signal is received, the SJB unlocks the driver door. If the unlock signal is received again within 3 seconds of the first unlock, the SJB unlocks all doors. If the lock signal is received, the SJB locks all doors.
If the signal received is from the panic button, the SJB cycles ground to the parking lamps and horn. The parking lamps and horn continue to cycle until the panic button is pressed again, the key is turned to the RUN position or 2 minutes and 45 seconds have elapsed.