B153F

DTC B153F

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 Descriptors
DTC B153F 02
- Liftgate Object Sensor Signal Circuit Short to Ground

DTC B153F 05
- Liftgate Object Sensor Signal Circuit Short to Battery or Open




Diagnostic Fault Information






Circuit/System Description

The liftgate object sensor uses 2 tape switches embedded in the liftgate opening weatherstrip to detect any foreign objects in the path of the liftgate. When pressure is applied to the weatherstrip, the tape switch is closed signaling the power liftgate module (LGM) that an object is in the path of the liftgate. The LGM will reverse the direction of the liftgate motor should this occur.


The 2 tape switches are placed in series between the liftgate object sensor signal circuit and the liftgate object low reference circuit. Each object sensor has a resistor as well as a switch. The resistors enable the LGM to perform diagnostic functions on the circuits. When both switches are open, voltage supplied by the LGM passes through the resistors and supplies the LGM with a reference voltage. If an object is in the path of the moving liftgate, the affected switch would close. The closing of the switch would bypass the resistor and change the reference voltage seen by the LGM, indicating that one of the switches is closed and an object has been detected.


Conditions for Running the DTC

Battery voltage must be between 9-16 volts.


Conditions for Setting the DTC

* DTC B153F 02 will set when the LGM detects a short to ground in the liftgate tape switch signal circuit.
* DTC B153F 05 will set when the LGM detects a short to voltage or an open/high resistance in the liftgate tape switch signal circuit.



Action Taken When the DTC Sets

The LGM will suspended power liftgate operation until the conditions for setting the DTC are no longer present. If the liftgate is in motion prior to the DTC setting, it will reverse and liftgate operation will be suspended.


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

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 left and right liftgate tape switches.
2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit terminal B and ground at the left liftgate tape switch harness connector.

• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the LGM.

3. Ignition ON, test for 5 volts between the signal circuit terminal A and ground at the right liftgate tape switch harness connector.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the LGM.

4. Ignition OFF, disconnect the X1 harness connector at the LGM.
5. Ignition ON, verify that a test lamp does not illuminate between the signal circuit terminal A and ground.

• If the test lamp illuminates, test the signal circuit for a short to voltage.

6. If all circuits test normal, test or replace the affected liftgate tape switch.



Component Testing

1. Ignition OFF, disconnect the harness connector at the right liftgate tape switch.
2. Test for 10K ohms of resistance between the signal terminal A and the low reference terminal B.

• If not within the specified range, replace the right liftgate tape switch.

3. Disconnect the harness connector at the left liftgate tape switch.
4. Test for 10K ohms of resistance between the signal terminal A and the low reference terminal B.

• If not within the specified range, replace the left liftgate tape switch.




Repair Instructions

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

* Liftgate Side Upper Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for LGM replacement, setup, and programming