Liftgate Handle Switch Malfunction
Liftgate Handle Switch Malfunction - 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 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 power liftgate handle switch circuit provides a single input to the liftgate control module. The liftgate handle switch is supplied a signal voltage, when the switch contact closes and the voltage drops, the liftgate control module detects the voltage drop and commands the liftgate to release.
Conditions for Running the DTC
The system voltage is 9-16 V.
Conditions for Setting the DTC
The liftgate handle switch signal circuit is active for greater than 30 seconds.
Action Taken When the DTC Sets
The liftgate control module will ignore the signal from the liftgate handle switch. Normal power liftgate operation will be available from the interior liftgate control switch or from a request from the remote keyless entry module.
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
* If the liftgate will not release from the closed position, refer to Opening the Liftgate Without Electrical Power Service and Repair for the appropriate procedure
* Whenever the liftgate control module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate control module.
* An intermittent short to ground in the Rear Liftgate Open/Close Switch circuit may cause the liftgate control module to command the liftgate to open if the vehicle is in park and the doors are unlocked. 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
Liftgate Schematics Liftgate Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left Front
Description and Operation
Liftgate Description and Operation Liftgate
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 Programming and Relearning for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the scan tool Liftgate Handle Switch parameter changes between Inactive to Active when pressing the liftgate unlatch switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S46B liftgate unlatch switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the low reference circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the low reference connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify the scan tool Liftgate Handle Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module.
2. Test for infinite resistance between the signal circuit terminal 2 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K39 liftgate control module.
• If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1.
6. Verify the scan tool Liftgate Handle Switch parameter is Active.
• If not Active
1. Ignition OFF, disconnect the harness connector at the K39 liftgate control module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K39 liftgate control module.
• If Active
7. Test or replace the S46B liftgate unlatch switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S46B liftgate unlatch switch.
2. Test for infinite resistance between the signal terminal 2 and the low reference terminal 1 with the switch in the open position.
• If less than infinite resistance
Replace the S46B liftgate unlatch switch.
• If infinite resistance
3. Test for less than 3 ohms between the signal terminal 2 and the low reference terminal 1 with the switch in the closed position.
• If 3 ohms or greater
Replace the S46B liftgate unlatch switch.
• If less than 3 ohms
4. All OK
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 Programming and Relearning for liftgate control module replacement, setup and programming