Test No. 24: Power Door Lock Does Not Operate On Any Door
- Check DOOR fuse (20-amp) and GAUGE fuse (10-amp). Fuses are located in fuse/relay box at driver's side of instrument panel. See Figure. If fuses are okay, go to next step. If any fuse is defective, repair short in wiring for appropriate fuse. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS. Passenger's side Junction Block (J/B) Electronic Control Unit (ECU) is located at passenger's side of instrument panel. See Figure.
- Check wiring harness and electrical connectors for power door lock system. See POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Passenger's side Junction Block (J/B) Electronic Control Unit (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 locks operate properly, original passenger's side J/B ECU was defective. If power door locks still do not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU and power door lock system for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Repair wiring harness or electrical connector as necessary.