B2494 (Manual Liftgate)

DTC B2494 (MANUAL 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 liftgate release switch is an input to the body control module (BCM). The BCM supplies battery voltage to the signal circuit 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
System voltage to the PLGM must be 9-16 volts.

CONDITIONS FOR SETTING THE DTC
The Liftgate Release Switch signal circuit is active for longer than 10 minutes.

ACTION TAKEN WHEN THE DTC SETS
The liftgate open and close functions from the liftgate switch 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 Liftgate Release Sw parameter while pressing the Liftgate Release Switch. The reading should change between Active and Inactive.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector at the Liftgate Release switch.
2. Ignition ON, verify the scan tool Liftgate Release is Inactive.
- If not the specified value, test the signal circuit terminal for a short to ground. If the circuit tests normal, replace the BCM.
3. If all circuits test normal, test or replace the Liftgate Release switch.

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


REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Programming and Relearning Programming and Relearning