Power Liftgate
DTC B2494 (Power 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 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 module. The liftgate handle switch is supplied a signal voltage, when the switch contact closes and the voltage drops, the liftgate module detects the voltage drop and commands the liftgate to open.
Conditions for Running the DTC
The system voltage is 9-16 V.
Conditions for Setting the DTC
The liftgate open signal circuit is active for greater than 30 seconds.
Action Taken When the DTC Sets
The liftgate 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
Note: Before testing can be performed, the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power (Procedures) for the appropriate procedure.
Whenever the liftgate module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate module.
An intermittent short to ground in the Liftgate Handle Switch Signal circuit may cause the liftgate module to command the liftgate to open if the vehicle is in park and the doors are unlocked.
Reference Information
Schematic Reference
Liftgate Schematics (Liftgate Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Liftgate Description and Operation (Liftgate Description and Operation)
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
Ignition ON, observe the scan tool Liftgate Handle Switch parameter while pressing and releasing the exterior S46 liftgate handle switch. The parameter should change between Active and Inactive.
If the value is always Inactive or always Active, perform the Circuit/System Testing.
If the value changes between Active and Inactive while pressing and releasing the exterior S46 liftgate handle switch and the DTC is history, replace the exterior S46 liftgate handle switch.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the exterior S46 liftgate handle switch.
2. Ignition ON, verify the scan tool Liftgate Handle Switch 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 K39 liftgate module.
3. Connect a 3 A fused jumper wire between the signal circuit terminal 1 and ground, verify the scan tool Liftgate Handle Switch 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 K39 liftgate module.
4. If all circuits test normal, test or replace the exterior S46 liftgate handle switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the exterior S46 liftgate handle switch.
2. Test for infinite resistance between the signal terminal 1 and the low reference terminal 2 with the switch in the open position.
• If not the specified value, replace the exterior S46 liftgate handle switch.
3. Test for less than 2 ohm between the signal terminal 1 and the low reference terminal 2 with the switch in the closed position.
• If greater than the specified range, replace the exterior S46 liftgate handle switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Liftgate Release Switch Replacement (Liftgate Release Switch Replacement)
* Control Module References (Programming and Relearning) for liftgate module replacement, setup and programming