Test No. 29: Power Door Lock Does Not Operate Only On One Door
- Check door lock motor for the inoperative door lock. See DOOR LOCK MOTOR under COMPONENT TESTS. If door lock motor is okay, go to next step. If door lock motor is defective, replace door lock motor along with door lock assembly and recheck power door lock operation.
- Check wiring harness and electrical connectors between inoperative door lock motor and passenger's side Junction Block (J/B) Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Passenger's side J/B ECU is located at passenger's side of instrument panel. See Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck power door lock operation.
- Check passenger's side J/B ECU for proper voltage and input signals. See PASSENGER'S SIDE JUNCTION BLOCK ELECTRONIC CONTROL UNIT under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage and input signals do not exist, repair as necessary and recheck power door lock operation.
- Replace passenger's side J/B ECU with a known-good passenger's side J/B ECU and recheck power door lock operation. If power door lock operates properly, original passenger's side J/B ECU was defective. If power door lock still does not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU and door lock motor for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Repair wiring harness or electrical connector as necessary.