Tailgate Ajar Circuit Open

TAILGATE AJAR CIRCUIT OPEN

Tailgate Ajar Circuit Open:

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.

Q: Does the test light illuminate brightly?

YES: Go To 2
NO: Repair the Tailgate Switch Ground circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

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.

Q: Does the scan tool display TAILGATE AJAR SW: TRUE?

YES: Replace the Tailgate Lock Motor/Ajar Switch.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 3

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.

Q: Is the resistance below 5.0 ohms?

YES: Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the (G78) Tailgate Ajar Switch Sense circuit for an open.
Perform BODY VERIFICATION TEST - VER 1. Body Verification Test