*TAILGATE AJAR CIRCUIT OPEN
For a complete wiring diagram Refer to Section 8W.
Theory of Operation
The scan tool will display the door state NOT the switch state. It will display as True/False. True states that the door is ajar (open). False states that the door is NOT ajar (closed).
| Possible Causes |
| TAILGATE AJAR SWITCH GROUND CIRCUIT OPEN |
| (G78) TAILGATE AJAR SWITCH SENSE CIRCUIT OPEN |
| TAILGATE LOCK MOTOR/AJAR SWITCH |
| BODY CONTROL MODULE |
Diagnostic Test
1. OPEN TAILGATE SWITCH GROUND CIRCUIT
Disconnect the Tailgate Lock Motor/Ajar switch connector.
Using a 12-volt Test Light connected to 12-volts, test the Tailgate Switch Ground circuit.
Does the test light illuminate brightly?
Yes
- Go To2
No
- Repair the Tailgate Switch Ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
2. CHECK FOR OPEN TAILGATE AJAR SWITCH
With the scan tool in Data Display, read the TAILGATE AJAR SW state.
Connect a jumper wire between the Sense circuit and the Ground circuit.
Does the scan tool display TAILGATE AJAR SW: TRUE?
Yes
- Replace the Tailgate Lock Motor/Ajar Switch.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Go To3
3. CHECK FOR OPEN (G78) TAILGATE AJAR SWITCH SENSE CIRCUIT
Turn the ignition off.
Leave the jumper wire from the previous step connected.
Disconnect the Body Control Module C1 harness connector.
Measure the resistance between ground and the (G78) Tailgate Ajar Switch Sense circuit in the BCM C1 connector.
Is the resistance below 5.0 ohms?
Yes
- Replace the Body Control Module in accordance with service information.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Repair the (G78) Tailgate Ajar Switch Sense circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)