All doors neither lock nor unlock (BCM)

1. All doors neither lock nor unlock diagnostics

1. Pre-check and visual inspection

Verify that the battery voltage is normal.
If the battery voltage is not normal, charge or replace the battery.

Verify that the fuses are normal.
If an abnormal condition such as a blowout is found in a fuse, inspect or repair the cause of the abnormal condition before replacing the fuse.

Confirm that the ground point is normal.
Repair and clean the ground point if improperly installed or significantly dirty.

Verify that the harness connectors are normal.
Inspect for poor connections at the connectors, worn or bent harnesses, or split wires inside the harness shorted to other circuits.

Check for any interference from aftermarket electronic components such as two-way radios or lights.
Remove any aftermarket electronic components or turn OFF the power to ensure that there is no influence on inspections or operations.

Verify that the power door lock operation conditions are met.

2. Components inspection

Check the door lock fuse.
If an abnormal condition such as a blowout is found in a fuse, inspect or repair the cause of the abnormal condition before replacing the fuse.

Check the BCM.
Observe the DTC information, and inspect the BCM if a malfunction is found.

Check the wireless access module.
Observe the DTC information, and inspect the wireless access module if a malfunction is found.

Check the power door lock switch.
If a malfunction is found in the power door lock switch, replace it.

Check the door lock key switch.
If a malfunction is found in the door lock key switch, replace it.

3. Circuit inspection

Check the following circuits for an open circuit, short to the power supply, short to ground, and high resistance.
If a malfunction is found in the circuit, repair or replace the applicable circuit.

  • Between the BCM and the power door lock switch
  • Between the power door lock switch and the ground
  • Between the BCM and the door lock key switch
  • Between the door lock key switch and the ground