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 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 9-18 V.
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 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.
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
Rear Hatch/Gate Description and Operation Rear Hatch/Gate
Electrical Information Reference
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Circuit Testing Circuit Testing
* Wiring Repairs Wiring Repairs
* Connector Repairs Connector Repairs
Scan Tool Reference
Control Module References Control Module References for 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 liftgate unlatch switch.
2. With the doors unlocked, command the liftgate latch to release by pressing the liftgate unlatch switch. The liftgate latch should release the liftgate.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S45B liftgate unlatch switch.
2. Test for less than 10 ohm between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Test for greater than 10V between the signal circuit terminal 2 and the ground circuit terminal 1.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
4. If all circuits test normal, test or replace the S45B liftgate unlatch switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S45B liftgate unlatch switch.
2. Test for infinite resistance between the signal terminal 2 and the ground terminal 1 with the switch in the open position.
• If not the specified value, replace the S45B liftgate unlatch switch.
3. Test for less than 2.0 ohm between the signal terminal 2 and the ground terminal 1 with the switch in the closed position.
• If greater than the specified range, replace the S45B liftgate unlatch switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic repair.
* Liftgate Release Switch Replacement Liftgate Release Switch Replacement
* Control Module References Control Module References for BCM replacement, setup and programming