B2494
DTC B2494
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)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.
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.
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 (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Testing
1. Ignition OFF, disconnect the harness connectors at the liftgate handle switch and liftgate close switch.
2. Ignition ON, verify that a test lamp illuminates between B+ and the low reference circuit terminal B.
• If the test lamp illuminate does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the LGM.
3. Ignition ON, verify that a test lamp illuminates between B+ and the low reference circuit terminal 2.
• If the test lamp illuminate does not illuminate, test the low reference circuit for a short to voltage or 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 (Verification Tests) after completing the diagnostic procedure.
* Liftgate Outside Handle Replacement (Service and Repair)
* Liftgate Actuator Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for LGM replacement, setup, and programming