Test No. 6: Each Door Does Not Lock & Unlock
- Check door lock motor on the inoperative power 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 assembly and recheck power door lock operation.
- Check wiring harness and electrical connectors between the inoperative door lock motor and body Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - PRIUS article. Body ECU is located at driver's side of instrument panel on the fuse/relay box and contains an 18-pin and 20-pin electrical connector. See Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary and recheck power door lock operation.
- Check body ECU for proper voltage and input signals. See BODY 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 body ECU with a known-good body ECU and recheck power door lock operation. If power door lock operates properly, original body ECU was defective. If power door lock still does not operate properly, check wiring harness and electrical connectors between body ECU and door lock motor for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - PRIUS article. Repair wiring harness or electrical connector as necessary.