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.

### DTC Descriptor

DTC B3125 01: Driver Door Only, Unlock Circuit Short to Battery
DTC B3125 02: Driver Door Only, Unlock Circuit Short to Ground
DTC B3125 04: Driver Door Only, Unlock Circuit Open
DTC B3130 01: All Unlock Circuit Short to Battery
DTC B3130 02: All Unlock Circuit Short to Ground
DTC B3130 04: All Unlock Circuit Open
DTC B3135 01: All Door Lock Circuit Short to Battery
DTC B3135 02: All Door Lock Circuit Short to Ground
DTC B3135 04: All Door Lock Circuit Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Door Lock Switch Signal | 1, 4 | 1, 4 | 1, 4 | --
Door Unlock Switch Signal | 2, 3, 4 | 2, 3, 4 | 2, 3, 4 | --
Driver Door Unlock Control | B3125 02 | B3125 04 | B3125 01 | --
Doors Lock Control | B3135 02, 4 | B3135 04, 4 | B3135 01, 4 | --
Passenger Doors Unlock Control | B3130 02 | B3130 04 | B3130 01 | --
Door Lock Switch Ground | -- | 1, 2, 3, 4 | 1, 2, 3, 4 | --
1. Door Lock Malfunction 2. Driver Door Unlock Malfunction 3. Door Unlock Malfunction 4. Fuel Filler Door Release Inoperative

### Circuit/System Description

The body control module (BCM) controls the door lock, passenger door unlock and driver door unlock circuits. Voltage is applied to the appropriate circuit when the BCM senses a door lock/unlock switch activation or a keyless entry lock or unlock command.

### Conditions for Running the DTC

The system voltage is 9-18 V.

### Conditions for Setting the DTC

#### B3125 01

The BCM detects a short to battery on the driver door unlock control circuit.

#### B3125 02

The BCM detects a short to ground on the driver door unlock control circuit.

#### B3125 04

The BCM detects an open circuit on the driver door unlock control circuit.

#### B3130 01

The BCM detects a short to battery on the unlock door control circuit.

#### B3130 02

The BCM detects a short to ground on the unlock door control circuit.

#### B3130 04

The BCM detects an open circuit on the unlock door control circuit.

#### B3135 01

The BCM detects a short to battery on the door lock control circuit.

#### B3135 02

The BCM detects a short to ground on the door lock control circuit.

#### B3135 04

The BCM detects an open circuit on the door lock control circuit.

### Action Taken When the DTC Sets

The power door locks will be inoperative

### Conditions for Clearing the DTC

• | This DTC will be current for as long as the fault is present.

• | When the fault is no longer present, the DTC will be a history DTC.

• | A history DTC will clear after 50 ignition cycles.

### Reference Information

#### Schematic Reference

Door Lock/Indicator Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Power Door Locks Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Verification

Command the driver door and passenger door lock actuators to Lock and Unlock with the scan tool, the doors should perform the Lock and Unlock function.

⇒ | If any door will not lock, refer to Door Lock Circuit Malfunction.

⇒ | If any door will not unlock, refer to Door Unlock Circuit Malfunction.

⇒ | If any door will not lock or unlock, refer to Door Lock/Unlock Circuit Malfunction

### Circuit/System Testing

1. Ignition OFF, disconnect the malfunctioning door latch connector.
2. Connect a test lamp between the appropriate door lock control circuit and the unlock control circuit.

• | A23D Door Latch Assembly - Driver terminals 2 and 3.

• | A23P Door Latch Assembly - Passenger terminals 7 and 8.

• | A23LR Door Latch Assembly - Left Rear terminals 2 and 3.

• | A23RR Door Latch Assembly - Right Rear terminals 7 and 8.

3. Command the doors to Unlock with a scan tool. The test lamp should briefly illuminate when commanding the Unlock state.

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM).

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 Body Control Module (BCM).

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

### Component Testing

#### Door Latch Test

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

⇒ | If the function does not perform as specified, replace the door lock.

3. Reverse the jumper wires; the appropriate door lock should perform the Unlock/Lock function.

⇒ | If the function does not perform as specified, replace the door lock.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Relay Replacement

• | Front Side Door Lock Replacement

• | Rear Door Lock Replacement

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