Fuel Door: Testing and Inspection

Fuel Filler Door Release Malfunction

Diagnostic Instructions

- Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic approach.
- Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information







Circuit/System Description

The locking and unlocking of the fuel door is a function of the power door lock system. The fuel door unlatch actuator shares the circuit with the door latch unlock control circuit. The body control module (BCM), upon receipt of a lock switch lock or unlock signal, will switch the appropriate door latch, as well as a fuel filler door unlatch actuator control circuits to B+ voltage. The opposing side of the door latch and fuel filler door unlatch actuator is connected to ground provided by the BCM through the other the door latch control circuits, along with the fuel filler door unlatch actuator, will lock or unlock as commanded.

Reference Information

Schematic Reference

Release Systems Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel Fill Door Description and Operation

Electrical Information Reference

- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Command the door latches to LOCK and UNLOCK with a scan tool, Each interior door lock knob should move between LOCK and UNLOCK.
2. If any or all doors do not LOCK or UNLOCK, refer to Power Door Locks Malfunction (Dead Lock) Power Door Locks Malfunction (Without Dead Locks).
3. Command the door latches to LOCK and UNLOCK with a scan tool, the M27 fuel door release actuator should LOCK and UNLOCK while changing between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the X53 fuse block-rear.
2. Connect a test lamp between the control circuit terminal 31 and ground.
3. Command the door latches to LOCK with a scan tool, the test lamp should briefly illuminate while commanding the LOCK state.
4. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
5. If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K9 BCM.
6. Ignition OFF, connect the X2 harness connector at the X53 fuse block-rear and disconnect the M27 fuel door release actuator.
7. Connect a test lamp between the control circuit terminal 1 and ground.
8. Command the door latches to UNLOCK with a scan tool, the test lamp should briefly illuminate while commanding the UNLOCK state.
9. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, refer to Power Door Locks Malfunction (Dead Lock) Power Door Locks Malfunction (Without Dead Locks)
10. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Power Door Locks Malfunction (Dead Lock) Power Door Locks Malfunction (Without Dead Locks)
11. Connect a test lamp between the control circuit terminal 2 and ground.
12. Command the door latches to LOCK with a scan tool, the test lamp should briefly illuminate while commanding the LOCK state.
13. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the X53 fuse block-rear.
14. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the X53 fuse block-rear.
15. If all circuits test normal, test or replace the M27 fuel door release actuator.

Component Testing

Fuel door latch

1. Ignition OFF, disconnect the harness connector at the M27 fuel door release actuator.
2. Install a 25 A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the M27 fuel door release actuator should perform the LOCK and UNLOCK functions.
3. If it does not perform as specified, replace the M27 fuel door release actuator.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Front Compartment Fuse Block Replacement
- Fuel Tank Filler Door Replacement
- Control Module References for BCM replacement, setup, and programming