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 the diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Fuel Door Latch Lock Control | 1 | 1 | 1 | --
Fuel Door Latch Unlock Control | 1 | 1 | 1 | --
1. Fuel Door Latch Inoperative

### Circuit/System Description

The rear fuse block, upon receipt of a lock switch lock or unlock signal, will switch the fuel filler door release actuator control circuits to battery positive voltage. The opposing side of the fuel filler door release actuator is connected to ground provided by the rear fuse block through the other door lock actuator control circuit and will lock or unlock as commanded.

### Reference Information

#### Schematic Reference

Door Lock/Indicator 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

Ignition ON, command the doors to LOCK and UNLOCK with a scan tool. All doors and the fuel filler door should LOCK and UNLOCK when changing between the commanded states.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the fuel door latch actuator.
2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 2.
3. Ignition ON, command the door locks to LOCK and UNLOCK with a scan tool. The test lamp should illuminate while commanding the LOCK and UNLOCK states.

⇒ | If the test lamp is always ON, test either control circuit for a short to voltage. If the circuit tests normal, replace the rear fuse block.

⇒ | If the test lamp remains OFF, test either control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the rear fuse block.

4. If all circuits test normal, test or replace the fuel door latch actuator.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the fuel door latch actuator.
2. Install a 15A fused jumper wire between the lock control terminal 1 and 12 volts. Momentarily install a jumper wire between the unlock control terminal 2 and ground. The fuel door latch actuator should perform the LOCK/UNLOCK function.

⇒ | If the function does not perform as specified, replace the fuel door latch actuator.

3. Reverse the jumper wires. The fuel door latch actuator should perform the UNLOCK/LOCK function.

⇒ | If the function does not perform as specified, replace the fuel door latch actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel Tank Filler Door Lock Actuator Replacement

Control Module References for rear fuse block replacement, setup, and programming