B2494

DTC B2494

Diagnostic Instructions

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

DTC Descriptor
DTC B2494 02
- Liftgate Handle Switch Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The liftgate handle switch and liftgate close switch consists of parallel circuits that provide a single input to the liftgate control module (LGM). The LGM initiates a liftgate event based on inputs provided by the liftgate handle switch and the liftgate close switch. Power is supplied by the LGM to each switch via the open/close switch signal circuit. When the liftgate handle switch is activated, the switch contacts close, providing a common ground path for the signal circuit through the liftgate handle switch low reference circuit. When the liftgate close switch is activated, the switch contacts close, providing a common ground path for the signal circuit through the liftgate handle switch low reference circuit causing the liftgate to close. For more detailed information concerning power liftgate operation refer to Liftgate Description and Operation.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC B2494 02 will set when the LGM detects a short to ground in the open/close signal circuit or one of the switch inputs is active for 10 minutes or greater.

Action Taken When the DTC Sets

The LGM will disable the open/close switch signal input until the conditions for setting the DTC is no longer present.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

* DTC B2494 02 will set if the liftgate handle switch or liftgate close switch becomes stuck in the closed position.
* Whenever the LGM is disconnected or loses power, the ignition must be cycled OFF then ON.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the liftgate handle switch and liftgate close switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal B and ground at the liftgate handle switch harness connector.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the LGM.

3. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal A and ground at the liftgate close switch harness connector.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the LGM.

4. Ignition ON, verify the scan tool liftgate handle sw. status parameter is INACTIVE.

• If not the specified value, test the signal circuit at both switch harness connectors for a short to ground. If the circuit tests normal, replace the LGM.

5. Reconnect the liftgate handle switch harness connector.
6. Verify the scan tool liftgate handle sw. status parameter is INACTIVE.

• If not the specified value, test or replace the liftgate handle switch.

7. Reconnect the liftgate close switch harness connector.
8. Verify the scan tool liftgate handle sw. status parameter is INACTIVE.

• If not the specified value, test or replace the liftgate close switch.

9. If all circuits test normal, replace the LGM.

Component Testing

1. Ignition OFF, disconnect the harness connector at the liftgate handle switch.
2. Test for infinite resistance between the signal terminal A and the ground circuit terminal B with the switch in the open position.

• If not within the specified value, replace the liftgate handle switch.

3. Disconnect the harness connector at the liftgate close switch.
4. Test for infinite resistance between the signal terminal B and the ground circuit terminal A with the switch in the open position.

• If not within the specified value, replace the liftgate close switch.

Repair Instructions

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

* Liftgate Outside Handle Replacement
* Liftgate Actuator Switch Replacement
* Control Module References for LGM replacement, setup, and programming. Programming and Relearning