Volt

DTC B3618

When the vehicle is in service mode, the body control module (BCM) supplies a signal to the tailgate handle switch through the rear closure handle switch open signal circuit. When the tailgate handle switch is pressed, the voltage within the signal circuit is pulled low and in response, the BCM will energise the tailgate release relay.

The system voltage is 9-16 V.

The BCM detects a short to ground in the rear closure handle switch open signal circuit for greater than 60 seconds

The rear hatch will not open when the tailgate handle switch is pressed.

Schematic Reference

Release Systems Schematics : Tailgate Schematics → Release System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Rear Hatch/Gate Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Vehicle in Service Mode, observe the scan tool Boot Lid/Tailgate Window Exterior Unlatch Switch parameter while pressing and releasing the S46 tailgate handle switch. The parameter should change between Active and Inactive each time the switch is pressed and released.

1. Vehicle OFF, disconnect the harness connector at the S46 tailgate handle switch.
2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Vehicle in Service Mode, verify the scan tool Boot Lid/Tailgate Window Exterior Unlatch Switch parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K9 BCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2. Verify the scan tool Boot Lid/Tailgate Window Exterior Unlatch Switch parameter is Active.

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

5. If all circuits test normal, test or replace the S46 tailgate handle switch.

Boot Release Switch

1. Vehicle OFF, disconnect the harness connector at the S46 tailgate handle switch.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 2 with the switch in the open position.

⇒	If not the specified value, replace the S46 tailgate handle switch.

3. Test for less than 2 Ω between the signal terminal 1 and the ground terminal 2 with the switch in the closed position.

⇒	If greater than the specified range, replace the S46 tailgate handle switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.