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 B3140 00: Door Unlock Switch Circuit
DTC B3150 00: Door Lock Switch Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Door Lock Switch Signal | B3150 00 | B3150 00, | B3150 00 | --
Door Unlock Switch Signal | B3140 00 | B3140 00 | B3140 00 | --
Driver Door Unlock Control | B3125 02 | 1, 2, 3 | 1, 2, 3 | --
Doors Lock Control | B3135 02 | 1, 2, 3 | 1, 2, 3 | --
Passenger Doors Unlock Control | B3130 02 | 1, 2, 3 | 1, 2, 3 | --
Doors Dead Lock Control | B3797 02 | 1, 2, 3 | 1, 2, 3 | --
Door Lock Switch Ground | -- | 1, 2, 3 | 1, 2, 3 | --
1. Door Lock Malfunction 2. Driver Door Unlock Malfunction 3. Door Unlock Malfunction

### Circuit/System Description

The door lock switch located in the hazard switch sends a ground signal to the body control module (BCM) whenever the door lock or door unlock switch is activated. 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 must be between 9-16 V.

### Conditions for Setting the DTC

#### B3140 00

The BCM detects a short to ground in the door lock switch unlock signal circuit.

#### B3150 00

The BCM detects a short to ground in the door lock switch lock signal circuit.

### Action Taken When the DTC Sets

• | The BCM stores the DTC to memory.

• | The power door locks will not operate.

### Conditions for Clearing the DTC

• | This DTC will change from current to history when the fault is no longer present.

• | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

### 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 Switch, Passenger Door Lock Switch, Driver Door Unlock Switch and Passenger Door Unlock Switch parameters while using the door lock switch. The reading should change between Inactive and Active.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X1 at the S26 Hazard Warning Switch.
2. Ignition ON, verify the scan tool Driver Door Lock Switch parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 9for a short to ground. If the circuit tests normal, replace the K9 Body Control Module (BCM).

3. Verify the scan tool Driver Door Unlock Switch parameter is Inactive.

⇒ | If not the specified value, test the signal circuit terminal 11 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 S26 Hazard Warning Switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector X1 at the S26 Hazard Warning Switch.
2. Test for infinite resistance between the signal terminals 9 and 11 and the ground terminal 1 with the switch in the open position.

⇒ | If less than the specified value, replace the S26 Hazard Warning Switch.

3. Test for less than 2 Ω between the signal terminal 9 and the ground terminal 1 with the switch in the unlock position.

⇒ | If greater than the specified range, replace the S26 Hazard Warning Switch.

4. Test for less than 2 Ω between the signal terminal 11 and the ground terminal 1 with the switch in the lock position.

⇒ | If greater than the specified range, replace the S26 Hazard Warning Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Hazard Warning Switch Replacement

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