B153B

Liftgate Full Open Switch Malfunction - DTC B153B

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 Descriptors

DTC B153B 02
- Liftgate Open Switch Signal Circuit Short to Ground

DTC B153B 05
- Liftgate Open Switch Signal Circuit Open

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 liftgate control module provides a low reference circuit and when the switch contacts close, the signal circuit goes low and the liftgate control module determines the switch to be active.

Conditions for Running the DTC

* The system voltage is 9-16 V.

* Power open or close operation is attempted.

Conditions for Setting the DTC

B153B 02

The liftgate control module detects a short to ground in the full open switch signal circuit.

B153B 05

The liftgate control module detects an open/high resistance in the full open switch signal circuit or the liftgate full open low reference circuit.

Action Taken When the DTC Sets

The power liftgate will not power close.

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

DTC B153B may also set due to a malfunctioning liftgate actuator clutch. The liftgate control module will command the liftgate to power open, the liftgate will release , the liftgate motor will hum, but will not open, when the liftgate module does not detect the full open signal of the liftgate actuator switch, it will set B153B.

Note: Before testing can be performed the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power Service and Repair for the appropriate procedure.

Whenever the liftgate control module loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the liftgate control module.

Reference Information

Schematic Reference

Liftgate Schematics Liftgate Schematics

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

Rear Hatch/Gate Description and Operation Rear Hatch/Gate

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

1. Ignition ON, observe the scan tool LGM Full Open Switch parameter while opening and closing the liftgate. The parameter should change between Active and Inactive.

• If the value does not change, perform the Circuit/System Testing.

2. With the liftgate closed, command the liftgate to power open by pressing the liftgate handle switch. The liftgate should power open.

• If the liftgate releases, hums but does not power open, refer to Liftgate Motor Clutch Malfunction - DTC B396B B396B

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the liftgate actuator switch.

2. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.

• If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the liftgate control module.

3. Ignition ON, verify that the scan tool LGM Full Open 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 liftgate control module

4. Connect a 3 A fused jumper wire between the signal circuit terminal 1 and ground, verify that the scan tool LGM Full Open 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 liftgate control module

5. If all circuits test normal, replace the liftgate actuator switch.

Repair Instructions

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

* Liftgate Actuator Replacement Liftgate Actuator Replacement

* Control Module References Programming and Relearning for liftgate control module replacement, programming and setup