GM Service Manual Online
For 1990-2009 cars only

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 B3150 5A: Central Door Lock Switch Stuck

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Door Lock Relay B+

B004A 00

4

--

--

Door Unlock Relay B+

B004A 00

4

--

--

Central Door Lock Switch Lock/Unlock Signal

B3150 5A

1

1

--

Door Lock Relay Control

2

B004A 00

4

--

Door Lock Indicator Control

3

3

3

--

Door Unlock Relay Control

2

B004A 00

4

--

Lock Control

2

2

2

--

Unlock Control

2

2

2

--

Door Lock Relay Ground

--

4

4

--

Door Unlock Relay Ground

--

4

4

--

Multifunction I/P Switch Ground

--

1,3

1,3

--

1. Central Door Lock Switch Inoperative

2. Door Locks Inoperative

3. Door Lock Indicator Malfunction

4. Crash Unlock Malfunction

Circuit/System Description

When the central door lock switch is pressed, the instrument panel cluster (IPC) will detect a voltage drop on the central door lock signal circuit, it will then send a serial data message to the rear fuse block. The rear fuse block upon receipt of a lock or unlock message will then provide voltage and ground to the appropriate lock or unlock control circuit to cause the doors to perform the lock or unlock functions.

Conditions for Running the DTC

The system voltage must be between 9-16 volts.

Conditions for Setting the DTC

The IPC receives a LOCK or UNLOCK command for greater than 2 minutes.

Action Taken When the DTC Sets

The power door locks 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 become 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 CDLS Switch Status (Central Door Locking System) while pressing the central door lock switch. The parameter should change to On while the switch is being pressed and change to Off when the switch is released.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the I/P multifunction switch.
  2. Ignition ON, verify the scan tool CDLS Switch Status parameter is Off.
  3. If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the instrument panel cluster.
  4. Connect a 3A fused jumper wire between the signal circuit terminal 5 and ground, verify the CDLS Switch Status parameter is On.
  5. If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the instrument panel cluster.
  6. If all circuits test normal, test or replace the I/P multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Accessory Switch Replacement

Control Module References for IPC replacement, setup and programming