B2494 (Power Liftgate)

DTC B2494 (POWER LIFTGATE)

DIAGNOSTIC INSTRUCTIONS
- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
- Review Strategy Based Diagnosis for an overview of the diagnostic approach.
- 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 button and exterior liftgate handle switch are parallel circuits and provide a single input to the power liftgate module (PLGM). The liftgate switches are supplied voltage and share a common low reference circuit from the PLGM. When the switch contacts close, the PLGM detects the voltage drop and commands the liftgate to open or close depending upon the position of the liftgate at the time.

CONDITIONS FOR RUNNING THE DTC
System voltage to the PLGM must be 9-16 volts.

CONDITIONS FOR SETTING THE DTC
The liftgate open/close signal circuit is active for longer than 10 minutes.

ACTION TAKEN WHEN THE DTC SETS
The liftgate open and close functions from the liftgate switches will be inoperative.

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 status code.
- A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.

CIRCUIT/SYSTEM VERIFICATION
Ignition ON, observe the scan tool Endgate Handle Sw parameter while pressing and depressing the Liftgate Switches. The reading should change between Active and Inactive.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connectors at the liftgate exterior switch and liftgate interior switch.
2. Ignition ON, verify the scan tool Endgate Handle Sw parameter is Inactive.
- If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the PLGM.
3. Ignition OFF, connect the harness connector at the appropriate liftgate switch.
4. Ignition ON, press and depress the appropriate liftgate switch, the reading should change between Active and Inactive.
- If the reading does not change between Active and Inactive, test or replace the appropriate liftgate switch.

COMPONENT TESTING
1. Ignition OFF, disconnect the harness connector at the appropriate liftgate switch.
2. Test for infinite resistance between the signal terminal 1 and the low reference circuit terminal 2 with the switch in the open position.
- If not the specified value, replace the appropriate liftgate switch.
3. Test for less than 2.0 ohms between the signal terminal 1 and the low reference circuit terminal 2 with the switch in the closed position.
- If greater than the specified range, replace the appropriate liftgate switch.


REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Liftgate Outside Handle Replacement
- Programming and Relearning Programming and Relearning