For 1990-2009 cars

## Power Door Locks Inoperative Without Door Lock Switches

### 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 provide an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Door Lock Actuator - Driver - Lock Control | 1 | 1 | 1 | --
Door Lock Actuator - Passenger - Lock Control | 1 | 1 | 1 | --
Door Lock Actuator - Driver - Unlock Control | 1 | 1 | 1 | --
Door Lock Actuator - Passenger - Unlock Control | 1 | 1 | 1 | --
Driver Door Jamb Switch Signal | 2 | 2 | 2 | --
Passenger Door Jamb Switch Signal | 2 | 2 | 2 | --
Remote Control Door Lock Receiver (RCDLR) Voltage Supply | 3 | 3 | 3 | --
Driver Door Latch Ground | -- | 2 | 2 | --
Passenger Door Latch Ground | -- | 2 | 2 | --
Remote Control Door Lock Receiver (RCDLR) Ground | -- | 3 | 3 | --
1. Power Door Locks Malfunction 2. Door Ajar Indicator Malfunction 3. Keyless Entry System Inoperative

### Circuit/System Description

The DOOR LKS fuse supplies battery positive voltage to the body control module (BCM) for the power door lock system. The power door locks are controlled by the Keyless Entry Transmitter only. There are no separate driver or passenger door lock switches.

The BCM, upon receipt of a lock or unlock signal from the remote control door lock receiver (RCDLR), will switch the appropriate door lock/unlock relay coil control circuit to ground causing the appropriate door lock/unlock relay to energize. With the relay energized, voltage is applied to the door lock actuator control circuit causing the door to either lock, or unlock depending on what command was received from the RCDLR. When a power door lock/unlock relay is not energized, the switch contacts are normally grounded through the BCM which provides ground to the appropriate door lock actuator for the lock/unlock function being performed. The power door lock/unlock functions are performed by reversing the flow of voltage through the door lock actuator control circuits. The BCM has three internal drivers for the power door lock system. Driver door unlock, passenger door unlock and all door lock. This is done to isolate the driver door lock actuator so it can be unlocked separately from the passenger door. For additional information concerning keyless entry, refer to Keyless Entry System Description and Operation .

### Reference Information

#### Schematic Reference

Door Lock/Indicator Schematics

#### Connector End View Reference

Vehicle Access Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data Definitions

• | Scan Tool Data List

• | Scan Tool Output Controls

### Circuit/System Testing

#### Power Door Locks Malfunction

1. Ignition OFF, disconnect the C4 harness connector at the BCM.
2. Test for less than 1 ohm of resistance between the ground circuit terminal E12 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition OFF, disconnect the inoperative door lock actuator harness connector.
4. Test for less than 1 ohm of resistance between the door lock actuator LOCK control circuit and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

5. Test for less than 1 ohm of resistance between the door lock actuator UNLOCK control circuit and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

6. Connect a test lamp between the inoperative door lock actuator lock and unlock control circuits at the inoperative door lock actuator harness connector.
7. Ignition ON, perform the Door LOCK and UNLOCK test with a scan tool. The test lamp should illuminate as the lock and unlock test is performed.

⇒ | If the test lamp remains OFF during either of the commands and the circuit fuse is good, test for a short to ground on either control circuit. If the circuits test normal, replace the BCM.

⇒ | If the test lamp is always OFF and the circuit fuse is open, test the control circuits for a short to ground. If the circuits test normal, replace the BCM.

8. If all circuits test normal, test or replace the door lock actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Side Door Lock Replacement

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

## Power Door Locks Inoperative With Door Lock Switches

### 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 provide an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Door Lock Actuator - Driver - Lock Control | 1 | 1 | 1 | --
Door Lock Actuator - Passenger - Lock Control | 1 | 1 | 1 | --
Door Lock Actuator - Driver - Unlock Control | 1 | 1 | 1 | --
Door Lock Actuator - Passenger - Unlock Control | 1 | 1 | 1 | --
Door Lock/Unlock Signal | 4 | 4 | 4 | --
Driver Door Jamb Switch Signal | 2 | 2 | 2 | --
Passenger Door Jamb Switch Signal | 2 | 2 | 2 | --
Remote Control Door Lock Receiver (RCDLR) Voltage Supply | 3 | 3 | 3 | --
Driver Door Latch Ground | -- | 2 | 2 | --
Passenger Door Latch Ground | -- | 2 | 2 | --
Remote Control Door Lock Receiver (RCDLR) Ground | -- | 3 | 3 | --
1. Power Door Lock Malfunction 2. Door Ajar Indicator Malfunction 3. Keyless Entry System Inoperative 4. Power Door Lock Switch Malfunction

### Circuit/System Description

The DR LCK fuse supplies battery voltage to the body control module (BCM) for the power door lock system. The BCM supplies and monitors a reference voltage to the driver and passenger door lock switches through the door lock switch lock/unlock signal circuit. Each of the door lock switches receives ground at G300 which is also the ground for the door lock and unlock relays located in the BCM. When a door lock switch is placed in the lock position, the reference voltage is switched to ground and the BCM senses 0.0 volts on the door lock/unlock signal circuit. When a door lock switch is placed in the unlock position, the reference voltage is switched to ground through a 1.5k ohm resistor that is internal to each of the door lock switches and the BCM senses approximately 2.9 volts on the door lock/unlock signal circuit. The BCM interprets what position the activated door lock switch was placed in based on the voltage drop.

The BCM, upon receipt of a lock or unlock switch signal, will switch the appropriate door lock/unlock relay coil control circuit to ground causing the appropriate door lock/unlock relay to energize. With the relay energized, voltage is applied to the door lock actuator control circuit causing the door to either lock, or unlock depending on what command was received from the power door lock switch or remote control door lock receiver (RCDLR). When a power door lock/unlock relay is not energized, the switch contacts are normally grounded through the BCM which provides ground to the appropriate door lock actuator for the lock/unlock function being performed. The power door lock/unlock functions are performed by reversing the flow of voltage through the door lock actuator control circuits. The BCM has three internal drivers for the power door lock system. Driver door unlock, passenger door unlock and all door lock. This is done to isolate the driver door lock actuator so it can be unlocked separately from the passenger door. For additional information concerning keyless entry, refer to Keyless Entry System Description and Operation .

### Reference Information

#### Schematic Reference

Door Lock/Indicator Schematics

#### Connector End View Reference

Vehicle Access Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Ignition ON, observe the Door Lock switch parameter while activating the appropriate door lock switch to the LOCK and UNLOCK positions. The reading should change between LOCK and UNLOCK.

⇒ | If the reading does not change as the switch is activated, refer to Power Door Lock Switch Malfunction.

2. Ignition ON, command the Door Latch to Lock and Unlock with the scan tool, the door should LOCK and UNLOCK.

⇒ | If the door does not Lock and Unlock when changing between commanded states, refer to Power Door Lock Malfunction.

### Circuit/System Testing

#### Power Door Lock Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative door lock switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal A and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool door lock switch parameter is IDLE.

⇒ | If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3-amp fused jumper wire between the signal circuit terminal C and the ground circuit terminal A. Verify the scan tool door lock switch parameter is LOCK.

⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the appropriate door lock switch.

#### Power Door Lock Malfunction

1. Ignition OFF, disconnect the C4 harness connector at the BCM.
2. Test for less than 1 ohm of resistance between the ground circuit terminal E12 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition OFF, disconnect the inoperative door lock actuator harness connector.
4. Test for less than 1 ohm of resistance between the door lock actuator LOCK control circuit and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

5. Test for less than 1 ohm of resistance between the door lock actuator UNLOCK control circuit and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

6. Connect a test lamp between the inoperative door lock actuator lock and unlock control circuits at the inoperative door lock actuator harness connector.
7. Ignition ON, perform the Door LOCK and UNLOCK test with a scan tool. The test lamp should illuminate as the lock and unlock test is performed.

⇒ | If the test lamp remains OFF during either of the commands and the circuit fuse is good, test for a short to ground on either control circuit. If the circuits test normal, replace the BCM.

⇒ | If the test lamp is always OFF and the circuit fuse is open, test the control circuits for a short to ground. If the circuits test normal, replace the BCM.

8. If all circuits test normal, test or replace the door lock actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Door Lock Switch Replacement

• | Front Side Door Lock Replacement

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