Test No. 29: Door Key Related Function Does Not Operate
- Check multiplex control system to see if Diagnostic Trouble Code (DTC) B1222 (Toyota hand-held tester) or DTC No. 22 (open door indicator light) exists when operating door key lock and unlock switch on driver's side front door by using ignition key to lock and unlock the door lock assembly. See MULTIPLEX CONTROL SYSTEMS - SEQUOIA article. If DTC is not output when operating door key lock and unlock switch, contacts are defective in the door key lock and unlock switch. If DTC is output when door key lock and unlock switch is not being operated, this indicates door key lock and unlock switch is stuck. If DTC is not output when operating door key lock and unlock switch or DTC exists when not operating door key lock and unlock switch, go to next step. If DTC is output when operating door key lock and unlock switch, go to step 4.
- Check door key lock and unlock switch on driver's side front door. See DOOR KEY LOCK & UNLOCK SWITCH under COMPONENT TESTS. If door key lock and unlock switch is okay, go to next step. If door key lock and unlock switch is defective, replace door key lock and unlock switch and recheck operation of door key related functions.
- Check wiring harness and electrical connectors between door key lock and unlock switch on driver's side front door and driver's door Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - SEQUOIA article. Driver's door ECU is located on the door and is incorporated into the power window switch assembly. See Figure. If wiring harness and electrical connector are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck operation of door key related functions.
- Check driver's door ECU for proper voltage and input signals. See DRIVER'S DOOR 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 operation of door key related functions.
- Replace driver's door ECU with a known-good door ECU and recheck operation of door key related functions. If door key related functions operate properly, original driver's door ECU was defective. If door key related functions still do not operate properly, check wiring harness and electrical connectors for driver's door ECU for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - SEQUOIA article. Repair wiring harness or electrical connector as necessary.