Manual Liftgate

DTC B2494 (Manual Liftgate)

Diagnostic Instructions

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

DTC Descriptor
DTC B2494 00
- Liftgate Handle Switch Circuit

Diagnostic Fault Information





Circuit/System Description

The liftgate release switch is an input to the body control module (BCM). The BCM supplies battery voltage to the signal circuit and when the release switch is activated the signal circuit voltage goes low. The BCM controls the liftgate release actuator through the liftgate latch release relay. When the release switch signal is activated, the BCM enables the liftgate latch release relay by applying battery voltage to the liftgate latch release relay supply circuit and the relay is energized when the BCM grounds the liftgate latch release relay control circuit. When the relay is energized battery voltage is supplied to the liftgate release actuator through the liftgate release actuator control circuit.

Conditions for Running the DTC

The system voltage is 9-18 volts.

Conditions for Setting the DTC

The liftgate release switch signal circuit is active for longer than 10 minutes.

Action Taken When the DTC Sets

The liftgate latch will malfunction.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Diagnostic Aids

Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power (Procedures) for the appropriate procedure.

Reference Information
Schematic Reference

Release Systems Schematics (Release Systems Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Rear Hatch/Gate Description and Operation (Rear Hatch/Gate Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Liftgate Handle Sw. parameter while pressing the exterior liftgate switch. The reading should change between Active and Inactive.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the exterior liftgate switch.
2. Test for less than 1.0 ohm between the ground circuit terminal 2 and ground.

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

3. Ignition ON, verify the scan tool Liftgate Handle Sw. 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 BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2. Verify the scan tool Liftgate Handle Sw. 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 BCM.

5. If all circuits test normal, test or replace the exterior liftgate switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the exterior liftgate 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 exterior liftgate switch.

3. Test for less than 2.0 ohms 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 exterior liftgate switch.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Programming and Relearning (Programming and Relearning) for BCM replacement, setup, and programming