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Makes 🢒 GMC_Truck 🢒 2008 🢒 Yukon - 4WD 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Liftgate/Liftgate Window Ajar Indicator Malfunction

Liftgate/Liftgate Window Ajar Indicator Malfunction Manual Liftgate

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 Ajar Switch Signal

1

1

1

--

Liftgate Window Latch Assembly Ground

--

1

1

--

Liftgate Latch Assembly Ground

--

1

1

--

1. Liftgate Ajar Indicator Malfunction

Circuit/System Description

The BCM receives a discrete input from 2 ajar switches to indicate the status of the liftgate. The liftgate ajar switches are normally open when the liftgate and liftglass are fully closed. When the liftgate or liftglass is opened, the ajar switch contacts close providing a path to ground. The instrument panel cluster (IPC) receives a serial data message from the BCM indicating the liftgate ajar status and the driver information center (DIC) will display the REAR ACCESS OPEN message.

Reference Information

Schematic Reference

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Door Ajar Indicator 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

Ignition ON, observe the scan tool Rear Closure Ajar Sw. parameter while opening and closing the liftgate and liftglass. The parameter should change from Inactive to Active.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
  2. Test for less than 1 ohm between the ground circuit terminal 5 and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Disconnect the harness connector at the liftgate window latch assembly.
  4. Test for less than 1 ohm between the ground circuit terminal 3 and ground.
    5. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  5. Ignition ON, verify the scan tool Rear Closure Ajar Sw. parameter is Inactive.
    6. ⇒If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the BCM.
  6. Connect a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Rear Closure Ajar Sw. 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 BCM.
  7. Ignition OFF, connect the harness connector at the liftglass window latch assembly.
  8. Ignition ON, observe the scan tool Rear Closure Ajar Sw. parameter while opening and closing the liftglass. The parameter should change from Inactive to Active
    9. ⇒If the value does not change, test or replace the liftglass window latch assembly.
  9. If all circuits test normal, test or replace the liftgate latch assembly.

Component Testing

Liftgate Latch Assembly

  1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
  2. Test for infinite resistance between the signal terminal 6 and ground terminal 5.
    3. ⇒If not the specified value, replace the liftgate latch assembly.
  3. Test for less than 2 ohms between the signal terminal 6 and ground terminal 5 with the switch in the closed position.
    4. ⇒If greater than the specified range, replace the liftgate latch assembly.

Liftgate Window Latch Assembly

  1. Ignition OFF, disconnect the harness connector at the liftgate window latch assembly.
  2. Test for infinite resistance between the signal terminal 4 and ground terminal 3.
    3. ⇒If not the specified value, replace the liftgate window latch assembly.
  3. Test for less than 2 ohms between the signal terminal 4 and ground terminal 3 with the switch in the closed position.
    4. ⇒If greater than the specified range, replace the liftgate window latch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Liftgate Window Latch Replacement
    •  Control Module References for BCM replacement, programming, and setup.

Liftgate/Liftgate Window Ajar Indicator Malfunction Power Liftgate

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

Liftglass Ajar Switch Signal

B396F 06

B396F 06

B396F 0B

--

Ratchet Switch Signal

1

B153A 08

1

--

Liftgate Window Latch Ground

--

B396F 06

1

--

1. Liftgate Ajar Indicator Malfunction

Circuit/System Description

The liftglass ajar switch is normally open when the liftglass is fully closed. When the liftglass is opened, the ajar switch contacts close providing a path to ground. The instrument panel cluster (IPC) receives a serial data message from the LGM indicating the liftglass ajar status and the driver information center (DIC) located at the bottom of the IPC, illuminates the rear access open message.

The liftgate module (LGM) detects the liftgate ratchet switch is closed to ground indicating the liftgate is open. The IPC receives a serial data message from the LGM indicating the liftgate ajar status and the driver information center (DIC) located at the bottom of the IPC, illuminates the rear access open message.

Reference Information

Schematic Reference

    •  Liftgate Schematics
    •  Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Door Ajar Indicator 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

Ignition ON, observe the scan tool LGM Latch Ratchet Sw. and the Liftgate Ajar Switch parameters while opening and closing liftgate and the liftglass. The parameters should change between Active and Inactive.

⇒If the LGM Latch Ratchet Sw parameter changes but the Liftgate Ajar Switch does not change, refer to the Liftglass Ajar Switch. Malfunction.
⇒If the LGM Latch Ratchet Sw and Liftgate Ajar Switch parameters do not change, refer to Liftgate Latch Assembly Malfunction.

Circuit/System Testing

Liftglass Ajar Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the liftglass latch assembly.
  2. Test for less than 5 Ω between the ground circuit terminal 3 and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool Liftgate Ajar Switch parameter is Inactive.
    4. ⇒If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the LGM.
  4. Install a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Liftgate Ajar Switch parameter is Active.
    5. ⇒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 LGM.
  5. If all circuits test normal, test or replace the liftglass latch assembly.

Liftgate Latch Assembly Malfunction

  1. Ignition OFF, disconnect the harness connector at the liftgate latch assembly.
  2. Ignition ON, verify the scan tool LGM Latch Ratchet Sw. parameter is Inactive.
    3. ⇒If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the LGM.
  3. Install a 3A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool LGM Latch Ratchet Sw. parameter is Active.
    4. ⇒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 LGM
  4. If all circuits test normal, test or replace the liftgate latch assembly.

Component Testing

Liftglass Latch Assembly

  1. Ignition OFF, disconnect the harness connectors at the liftglass latch assembly.
  2. Test for infinite resistance between the signal terminal 4 and ground terminal 3
    3. ⇒If not the specified value, replace the liftglass latch assembly.
  3. Test for less than 2 Ω between the signal terminal 4 and ground terminal 3 with the switch in the closed position
    4. ⇒If greater than the specified range, replace the liftglass latch assembly.

Liftgate Latch Assembly

  1. Ignition OFF, disconnect the harness connectors at the liftgate latch assembly.
  2. Test for infinite resistance between the signal terminal 6 and the low reference terminal 2.
    3. ⇒If not the specified value, replace the liftgate glass latch.
  3. Test for less than 2 Ω between the signal terminal 6 and the low reference terminal 2 with the switch in the closed position
    4. ⇒If greater than the specified range, replace the liftgate latch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for LGM replacement, setup, and programming