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 Descriptors

DTC B3140 00: Driver Unlock Switch Circuit
DTC B3145 00: Passenger Unlock Switch Circuit
DTC B3150 00: Driver Lock Switch Circuit
DTC B3155 00: Right Front Lock Switch Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Lock Relay and Unlock Relay B+ | 2 | 2 | -- | --
Driver Door Lock Switch Lock Signal | B3150 00 | B3150 00 | B3150 00 | --
Driver Door Lock Switch Unlock Signal | B3140 00 | B3140 00 | B3140 00 | --
Passenger Door Lock Switch Lock Signal | B3155 00 | B3155 00 | B3155 00 | --
Passenger Door Lock Switch Unlock Signal | B3145 00 | B3145 00 | B3145 00 | --
Driver Door Latch Control | 2 | 2 | 2 | --
Door Unlock Relay Control | B3130 00 | B3130 00 | B3130 00 | --
Driver Door Relay Unlock Control | B3125 00 | B3125 00 | B3125 00 | --
Door Lock Relay Control | B3135 00 | B3135 00 | B3135 00 | --
Passenger Door Latch Control | 2 | 2 | 2 | --
Driver Door Lock Switch Ground | -- | 1 | 1 | --
Lock Relay and Unlock Relay Ground | -- | 2 | 2 | --
Passenger Door Lock Switch Ground | -- | 1 | 1 | --
1. Door Lock Switch Malfunction 2. Door Latch Malfunction

### Circuit/System Description

The body control module (BCM) supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the reference voltage is taken directly to ground and the BCM detects the voltage drop on the signal circuit.

### Conditions for Running the DTC

The system voltage must be between 9-16 volts.

### Conditions for Setting the DTC

#### B3140 00 or B3150 00

The BCM detects a fault in the driver door lock switch lock or unlock signal circuits.

#### B3145 00 or B3155 00

The BCM detects a fault in the passenger door lock switch lock or unlock signal circuits.

### Action Taken When the DTC Sets

The driver or passenger door lock switch will malfunction.

### Conditions for Clearing the DTC

• | The 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

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Ignition ON, observe the scan tool Driver Door Lock Sw, Psgr Door Lock Sw, Driver Door Unlock Sw and Psgr Door Unlock Sw parameters while using the door lock switches. The parameter should change between Inactive and Active.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Ignition ON, verify the scan tool Door Lock Sw parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

3. Verify the scan tool Door Unlock Sw parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 2 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 1 and ground. Verify the scan tool Door Lock Sw parameter is Active.

⇒ | 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. Install a 3 amp fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Door Unlock Sw parameter is Active.

⇒ | 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.

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

### Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminals 2 and 1 and the ground terminal 3 with the switch in the at rest position.

⇒ | If less than the specified value, replace the door lock switch.

3. Test for less than 2 ohms between the signal terminal 1 and the ground terminal 3 with the switch in the lock position.

⇒ | If greater than the specified range, replace the door lock switch.

4. Test for less than 2 ohms between the signal terminal 2 and the ground terminal 3 with the switch in the unlock position.

⇒ | If greater than the specified range, replace the door lock switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Door Lock Switch Replacement

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