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Liftgate Release Malfunction

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Liftgate Release Relay B+

2

2

--

--

Rear Closure Handle Switch Open Signal

B3618 00

1

1

--

Tail Glass/Trunk Motor Release Control

B3265 02

2

2

--

Liftgate Latch Control

2

2

2

--

Rear Compartment Lid Release Switch Ground

--

1

--

--

Liftgate Latch Ground

--

2

--

--

Liftgate Release Relay Ground

--

2

--

--

1. Rear Compartment Lid Release Switch Malfunction

2. Liftgate Release Malfunction

Circuit/System Description

The body control module (BCM) supplies a reference voltage to the rear compartment lid unlatch switch through the release switch signal circuit. When the rear compartment lid unlatch switch is pressed, the release switch signal circuit is grounded through the rear compartment lid unlatch switch ground circuit and the reference voltage is pulled low within the BCM. In response, the BCM applies battery positive voltage to the liftgate release relay control circuit, which energizes the coil side of the relay. The switch side of the liftgate release relay then closes, supplying battery positive voltage through the relay and the liftgate latch control circuit activating the latch so that the liftgate may be manually opened.

Reference Information

Schematic Reference

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Rear Hatch/Gate Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, observe the scan tool Boot Lid/Liftglass Exterior Unlatch Switch parameter while pressing and releasing the S58A rear compartment lid unlatch switch-exterior. The parameter should be Inactive and change to Active when the switch is pressed.
  2. If the value does not change, refer to Liftgate Release Switch Inoperative.
  3. Command the M30 liftgate latch to UNLATCH with a scan tool. The M30 liftgate latch should release the liftgate.
  4. If the M30 liftgate latch does not release the deck lid, refer to Release Actuator Inoperative.

Circuit/System Testing

Liftgate Release Switch Inoperative

  1. Ignition OFF, disconnect the harness connector at the S58A rear compartment lid unlatch switch-exterior.
  2. Ignition ON, test for less than 10 Ω between the ground circuit terminal 1 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Verify the scan tool Trunk Lid/Liftglass Exterior Unlatch Switch parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K9 BCM.
  6. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Trunk Lid/Liftglass Exterior Unlatch Switch parameter is Active.
  7. 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.
  8. If all circuits test normal, test or replace the S58A rear compartment lid unlatch switch-exterior.

Release Actuator Inoperative

  1. Ignition OFF for 10 minutes, disconnect the KR95A liftgate release relay.
  2. Test for less than 10 Ω between the ground circuit terminal 85 and ground.
  3. If greater than the specified range, test for an open/high resistance.
  4. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 30 and ground.
  5. If the test lamp illuminates, test the control circuit for a short to voltage.
  6. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.
  7. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 30 for a short to ground. If the circuit tests normal, test or replace the KR95A liftgate release relay.
  8. Ignition OFF, disconnect the harness connector at the M30 liftgate latch.
  9. Test for less than 10 Ω between the ground circuit terminal 1 and ground.
  10. If greater than the specified range, test the ground circuit for an open/high resistance.
  11. Connect the harness connector at the M30 liftgate latch.
  12. Ignition ON, connect a 10 A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30. Verify the M30 liftgate latch is activated.
  13. If the M30 liftgate latch does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the M30 liftgate latch.
  14. Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
  15. Command the M30 liftgate latch to UNLATCH with a scan tool. The test lamp should turn ON during the UNLATCH command.
  16. 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.
  17. If all circuits test normal, test or replace the KR95A liftgate release relay.

Component Testing

Relay Test

  1. Ignition OFF, disconnect the KR95A liftgate release relay.
  2. Test for 60-180 Ω between terminals 85 and 86.
  3. If not within the specified range, replace the KR95A liftgate release relay.
  4. Test for infinite resistance between the following terminals:
  5. • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    If not the specified value, replace the KR95A liftgate release relay.
  6. Install a 5 A 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.
  7. If greater than the specified range, replace the KR95A liftgate release relay

Liftgate Latch

  1. Ignition OFF, disconnect the harness connector at the M30 liftgate latch.
  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 M30 liftgate latch activates.
  3. If the latch does not perform as specified, replace the M30 liftgate latch.

Liftgate Release Switch

  1. Ignition OFF, disconnect the harness connector at the S58A rear compartment lid unlatch switch-exterior.
  2. Test for infinite resistance between the signal terminal 2 and the ground terminal 1 with the switch in the open position.
  3. If not the specified value, replace the S58A rear compartment lid unlatch switch-exterior.
  4. Test for less than 2 Ω between the signal terminal 2 and the ground terminal 1 with the switch in the closed position.
  5. If greater than the specified range, replace the S58A rear compartment lid unlatch switch-exterior.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Relay Replacement : Within an Electrical Center → Attached to Wire Harness
    •  Liftgate Catch Replacement
    •  Liftgate Release Switch Replacement
    • Control Module References for BCM replacement, programming and setup
   


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