B2494
DTC B2494
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 Instructionsprovides an overview of each diagnostic category.
DTC Descriptor
DTC B2494 00
- Liftgate Handle Switch Circuit
Diagnostic Fault Information
Circuit/System Description
The BCM supplies a 12V signal to the signal circuit of the exterior liftgate handle switch 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 9-16 volts.
Conditions for Setting the DTC
The liftgate release switch signal circuit is active for greater than 30 seconds.
Action Taken When the DTC Sets
The BCM will ignore the signal from the exterior liftgate handle switch
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 become 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.
If the vehicle has a history of the liftgate opening unexpectedly, inspect the point where the wires enter the exterior liftgate handle switch for corrosion or evidence of water intrusion.
Reference Information
Schematic Reference
Release Systems Schematics Release Systems Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Liftgate Description and Operation 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
Control Module References Programming and Relearningfor scan tool information
Circuit/System Verification
1. DTC B2494 should not be set as a history DTC.
• If DTC B2494 is set only as history, replace the S45A liftgate handle switch--exterior.
2. Observe the scan tool Liftgate Handle Sw. parameter while pressing the S45A liftgate handle switch--exterior. The reading should change between Active and Inactive as the switch is pressed and released.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S45A liftgate handle switch--exterior.
2. Test for less than 1 ohm between the ground circuit terminal B 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 A for a short to ground. If the circuit tests normal, replace the K9 BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. 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 K9 BCM.
5. If all circuits test normal, test or replace the S45A liftgate handle switch--exterior.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S45A liftgate handle switch--exterior.
2. Test for infinite resistance between the signal terminal A and the ground terminal B with the switch in the open position.
• If not the specified value, replace the S45A liftgate handle switch--exterior.
3. Test for less than 2 ohms between the signal terminal A and the ground terminal B with the switch in the closed position.
• If greater than the specified range, replace the S45A liftgate handle switch--exterior.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Liftgate Release Switch Replacement Liftgate Release Switch Replacement
* Control Module References Programming and Relearningfor BCM replacement, setup, and programming