Cherokee 2WD L6-4.0L VIN S (1998)
Power Door Lock Actuator: Testing and Inspection
Before you proceed with this diagnosis, confirm proper power door lock switch operation. See Body and Frame/Locks/Power Locks/Door Module for
the diagnostic procedures. Remember, the Passenger Door Module (PDM) circuitry controls the output to each of the power lock motors.
1. Check each power lock motor for correct operation while moving the power lock switch to both the Lock and Unlock positions. If all of the power
lock motors are inoperative, go to Step 2. If one power lock motor is inoperative, go to Step 3.
2. If all of the power lock motors are inoperative, the problem may be caused by one shorted motor. Unplugging a shorted power lock motor from the
power lock circuit will allow the good power lock motor to operate. Unplug each power lock motor wire harness connector, one at a time, and
recheck both the lock and unlock functions by operating the power lock switch. If all of the power lock motors are still inoperative after the above
test, check for a short or open circuit between the power lock motors and the PDM. If unplugging one power lock motor causes the other motors to
become functional, go to Step 3 to test the unplugged motor.
3. Once it is determined which lock motor is inoperative, that motor can be tested as follows. Unplug the wire harness connector at the inoperative
motor. Apply 12 Volts to the motor terminals to check its operation in one direction. Reverse the polarity to check the operation in the other
direction. If OK, repair the short or open circuits to the PDM as required. If not OK, replace the faulty power lock motor.
