Test No. 11: Power Door Locks May Not Be Locked Or Unlocked When Using The Key, Or Two-Operation Unlock Function Does Not Operate

NOTE: Two-operation unlock function unlocks all doors. When using the key and turning driver's door lock once, only driver's door will unlock. Turning driver's door lock twice in succession will unlock both doors in simultaneously.

Check door unlock detection switch on driver's door and passenger's door. See DOOR UNLOCK DETECTION SWITCH under COMPONENT TESTS. If door unlock detection switches are okay, go to next step. If any door unlock detection switch is defective, replace door unlock detection switch and recheck operation of power door lock or two-operation unlock function.
Check wiring harness and electrical connectors between each door unlock detection switch and body Electronic Control Unit (ECU), and between door unlock detection switch and ground connection. See WIRING DIAGRAMS in POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - CARS article. Body ECU is located behind driver's side of instrument panel and contains 18-pin and 25-pin electrical connectors. See Figure. For body ECU electrical terminal identification, 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 operation of power door lock or two-operation unlock function.
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 operation of power door lock or two-operation unlock function.
Replace body ECU with a known-good body ECU and recheck operation of power door lock or two-operation unlock function. If power door lock or two-operation unlock function operates properly, original body ECU was defective. If power door lock or two-operation unlock function still does not operate properly, check wiring harness and electrical connectors for body ECU and door unlock detection switch for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - CARS article. Repair wiring harness or electrical connector as necessary.