For 1990-2009 cars

### 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Driver Door Unlock Signal | B3130 02 | 1 | 1 | --
Door Lock Signal | B3135 02 | 1 | 1 | --
1. Fuel Door Release Malfunction

### Circuit/System Description

The locking and unlocking of the fuel door is a function of the power door lock system. The fuel door release actuator shares the circuit with the driver door latch. 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 release actuator control circuits to B+ voltage. The opposing side of the door latch and fuel filler door release actuator is connected to ground provided by the BCM through the other the door latch control circuits, along with the fuel filler door release 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

Observe the operation of the power door locks and fuel filler door while using the power door lock switch. The fuel filler door should Lock and Unlock as commanded along with the door locks.

⇒ | If the power door locks do not lock and unlock, refer to Symptoms - Vehicle Access.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the M27 Fuel Door Release Actuator.
2. Connect a test lamp between the control circuit terminals 1 and 2.
3. Command the power door locks to Lock and Unlock using the power door lock switch. The test lamp should illuminate briefly for each command.

⇒ | If the test lamp does not illuminate, test the control circuits for an open/high resistance. If the circuits test normal, test or replace the M27 Fuel Door Release Actuator.

### Component Testing

#### Fuel Door Release Actuator Test

1. Ignition OFF, disconnect the harness connector at the M27 Fuel Door Release Actuator.
2. Install a 25 A fused jumper wire between the lock control terminal 2 and 12 V. Momentarily install a jumper wire between the unlock control terminal 1 and ground. The M27 Fuel Door Release Actuator should perform the Lock/Unlock function.

⇒ | If the function does not perform as specified, replace the M27 Fuel Door Release Actuator.

3. Reverse the jumper wires; the M27 Fuel Door Release Actuator should perform the Unlock/Lock function.

⇒ | If the function does not perform as specified, replace the M27 Fuel Door Release Actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Refer to LINK X Fuel Tank Filler Door Lock Actuator Replacement

• | Control Module References for BCM replacement, setup, and programming