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Test No. 2: Door Key Linked Function Does Not Operate

NOTE: Door key linked function allows all doors and back door to be locked and unlocked simultaneously by using key and turning door lock on driver's side front door or passenger's side front door.
  1. If door key linked function does not operate on driver's side front door, go to next step. If door key linked function does not operate on passenger's side front door, go to step  5.
  2. 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  8.
  3. 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 linked function.
  4. 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 step  8. If wiring harness or electrical connector are defective, repair as necessary and recheck operation of door key linked function.
  5. Check multiplex control system to see if Diagnostic Trouble Code (DTC) B1224 (Toyota hand-held tester) or DTC No. 24 (open door indicator light) exists when operating door key lock and unlock switch on passenger'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  8.
  6. Check door key lock and unlock switch on passenger'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 linked function.
  7. Check wiring harness and electrical connectors between door key lock and unlock switch on passenger's side front door and passenger's door Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - SEQUOIA article. Passenger'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 linked function.
  8. Check body Electronic Control Unit (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 operation of door key linked function.
  9. Replace body ECU with a known-good body ECU and recheck operation of door key linked function. If door key linked function operates properly, original body ECU was defective. If door key linked function still does not operate properly, check wiring harness and electrical connectors for body ECU and driver's or passenger's 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.
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