B153B

DTC B153B

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 B153B 02
Liftgate Open Switch Signal Circuit Short to Ground




DIAGNOSTIC FAULT INFORMATION

CIRCUIT/SYSTEM DESCRIPTION
The full open switch is part of the gear motor assembly and will close and become active when the liftgate reaches the full open position. The full open switch signal circuit is supplied battery voltage through a resistor and monitored within the liftgate control module. The power liftgate control module (PLGM) provides a low reference circuit and when the switch contacts close, the signal circuit goes low and the PLGM determines the switch to be active.

CONDITIONS FOR RUNNING THE DTC
- System voltage to the liftgate control module must be 9-16 volts
- Power open or close operation is attempted

CONDITIONS FOR SETTING THE DTC
The PLGM detects a short to ground in the full open switch signal circuit.

ACTION TAKEN WHEN THE DTC SETS
The power liftgate system will be disabled.

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.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the X3 harness connector at the PLGM.
2. Ignition ON, verify the scan tool Full Open Sw. parameter is INACTIVE.
- If not the specified value, replace the PLGM
3. Reconnect the X3 harness connector at the PLGM.
4. Open the liftgate and verify the scan tool Full Open Sw. parameter is ACTIVE.
- If not the specified value, test the signal circuit terminal 5 for a short to voltage or an open/high resistance. If the circuit tests normal, test the low reference circuit terminal 6 for an open/high resistance. If the circuits tests normal, test or replace the liftgate motor assembly.
5. Close the liftgate and verify the scan tool Full Open Sw. parameter is INACTIVE.
- If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, test or replace the liftgate motor assembly.
6. If all circuits test normal, replace the PLGM.


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

Programming and Relearning. Programming and Relearning