Volt

Hatch Release Malfunction

The BCM supplies a reference voltage to the tailgate handle switch through the rear closure handle switch open signal circuit. When the tailgate handle switch is operated, the rear closure handle switch open signal circuit is grounded through the tailgate handle switch ground circuit and the reference voltage is pulled low within the BCM. In response, the BCM applies battery positive voltage to the tailgate release relay control circuit, which energises the coil side of the tailgate release relay. The switch side of the tailgate release relay then closes, supplying battery positive voltage through the relay and the tailgate latch control circuit activating the latch so that the rear hatch may be manually raised to an open position.

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

1. Vehicle in Service Mode, observe the scan tool Boot Lid/Liftglass Exterior Unlatch Switch parameter while pressing and releasing the S46 tailgate handle switch. The parameter should change between Active and Inactive.

⇒	If the value does not change, refer to Tailgate Handle Switch Inoperative.

2. Command the rear hatch to release with a scan tool, the A23C tailgate latch assembly should release the rear hatch.

⇒	If the A23C tailgate latch assembly does not release the rear hatch, refer to Release Actuator Inoperative.

Tailgate Handle Switch Inoperative

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/Liftglass 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 ground. Verify the scan tool Boot Lid/Liftglass 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.

Release Actuator Inoperative

1. Vehicle OFF, disconnect the KR95A tailgate release relay.
2. Test for less than 10 Ω between the ground circuit terminal 48 and ground.

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

3. Vehicle in Service Mode, verify that a test lamp does not illuminate between the control circuit terminal 45 and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

4. Verify that a test lamp illuminates between the B+ circuit terminal 46 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Vehicle OFF, disconnect the harness connector at the A23C tailgate latch assembly.
6. Test for less than 10 Ω between the ground circuit terminal 1 and ground.

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

7. Connect the harness connector at the A23C tailgate latch assembly.
8. Vehicle in Service Mode, connect a 10 A fused jumper wire between the B+ circuit terminal 46 and the control circuit terminal 45. Verify the A23C tailgate latch assembly is activated.

⇒	If the A23C tailgate latch assembly does not activate and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the A23C tailgate latch assembly.

⇒	If the A23C tailgate latch assembly does not activate and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test or replace the A23C tailgate latch assembly.

9. Connect a test lamp between the control circuit terminal 44 and the ground circuit terminal 48.
10. Command the Boot Lid Unlatch to UNLATCH with a scan tool. The test lamp should turn ON during the UNLATCH command.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

11. If all circuits test normal, test or replace the KR95A tailgate release relay.

Relay Test

1. Vehicle OFF, disconnect the KR95A tailgate release relay.
2. Test for 60-200 Ω between terminals 85 and 86.

⇒	If not within the specified range, replace the KR95A tailgate release relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If less than the specified value, replace the KR95A tailgate release relay.

4. Install a 3A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.

⇒	If greater than the specified range, replace the KR95A tailgate release relay.

Rear Compartment Lid Latch

1. Vehicle OFF, disconnect the harness connector at the A23C tailgate latch assembly.
2. Install a 10 A fused jumper wire between the control terminal 3 and 12 V. Briefly install a jumper wire between the ground terminal 1 and ground. Verify the A23C tailgate latch assembly activates.

⇒	If the latch does not perform as specified, replace the A23C tailgate latch assembly.

Tailgate Handle 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.