Test No. 5: Back (Rear Liftgate) Door Opener Function Does Not Operate

NOTE: Back (rear liftgate) door may also be referred to as luggage compartment door.

Check back (rear liftgate) door motor. See BACK (REAR LIFTGATE) DOOR MOTOR under COMPONENT TESTS. If door lock motor is okay, go to next step. If door lock motor is defective, replace door lock motor along with door lock assembly and recheck operation of back (rear liftgate) door opener.
Check wiring harness and electrical connectors between back (rear liftgate) door motor and body Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - CARS article. Body ECU is located on instrument panel junction block and contains 12-pin, 22-pin and 25 pin electrical connectors. 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 back (rear liftgate) door opener.
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 back (rear liftgate) door opener.
Replace body ECU with a known-good body ECU and recheck operation of back (rear liftgate) door opener. If back (rear liftgate) door opener operates properly, original body ECU was defective. If back (rear liftgate) door opener still does not operate properly, check wiring harness and electrical connectors for body ECU and (rear liftgate) door motor for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS WITHOUT KEYLESS ENTRY - CARS article. Repair wiring harness or electrical connector as necessary.