B153B
DTC B153B
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 B153B 02
- Liftgate Open Switch Signal Circuit Short to Ground
DTC B153B 05
- Liftgate Open Switch Signal Circuit Short to Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
The ratchet, pawl, and sector switches are part of the latch motor assembly and are used by the liftgate control module (LGM) to determine the state of the latch during the process of latching or unlatching. Each of the latch switch signal circuits are supplied battery voltage through a resistor and monitored within the LGM. The latch switches share a common low reference circuit from the LGM and when the switch contacts close the signal circuit goes low and the LGM determines the switch to be active. The full open switch is a limit switch mounted on the gear motor assembly alongside the swing arm gear. The full open switch signal circuit is supplied battery voltage through a resistor and monitored within the LGM. When the liftgate reaches the full open position, the switch signal circuit is closed to the low reference circuit and the signal circuit voltage goes low.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
* DTC B153B 02 will set when the LGM detects a short to ground in the full open switch signal circuit.
* DTC B153B 08 will set when the LGM detects a short to voltage or an open/high resistance 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 condition responsible for setting the DTC no longer exists.
* You issue a scan tool CLEAR DTCs command.
Diagnostic Aids
Whenever the LGM loses power or is disconnected, 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 X3 harness connector at the LGM.
2. Ignition ON, verify the scan tool Full Open Sw. parameter is INACTIVE.
• If not the specified value, replace the LGM.
3. Reconnect the X3 harness connector at the LGM.
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 4 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 4 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 LGM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Liftgate Close Actuator Motor Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for LGM replacement, setup, and programming