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 Descriptors

DTC B3145: Right Front/Passenger Unlock Switch Circuit Low

DTC B3155: Right Front/Passenger Lock Switch Circuit Low

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Door Latch Control

1

1

B2517, 1

--

Driver Door Latch Enable Control

1

1

B2517, 1

--

Front Passenger Door Latch Control

1

1

B2518, 1

--

Front Passenger Door Latch Enable Control

1

1

B2518, 1

--

Driver Door Lock Switch Lock Signal

B3152, 2

2

2

--

Driver Door Lock Switch Unlock Signal

B3142, 2

2

2

--

Left Front Exterior Door Handle Switch Signal

B3849, 2

1

1

--

Left Front Interior Door Handle Switch Signal

B3848, 2

1

1

--

Passenger Door Lock Switch Lock Signal

B3155, 2

2

2

--

Passenger Door Lock Switch Unlock Signal

B3145, 2

2

2

--

Right Front Exterior Door Handle Switch Signal

B1474, 1

1

1

--

Right Front Interior Door Handle Switch Signal

B2981, 1

1

1

--

Door Handle Switch - Driver Exterior Ground

--

1

1

--

Door Handle Switch - Driver Interior Ground

--

1

1

--

Door Handle Switch - Passenger Exterior Ground

--

1

1

--

Door Handle Switch - Passenger Interior Ground

--

1

1

--

Door Lock Switch - Driver Ground

--

2

2

--

Door Lock Switch - Passenger Ground

--

2

2

--

1. Power Door Latch System Malfunction

2. Power Door Locks Inoperative

Circuit/System Description

The passenger door lock switch signal circuits provide inputs to the passenger door module (PDM) when the passenger door lock switch is activated to the Lock or Unlock position. These inputs allow the PDM to detect a door Lock or Unlock request. The PDM provides power to the passenger door lock switch. When the door lock switch is activated to the Lock or Unlock position, ground is supplied by G202. When the PDM detects low voltage on a signal circuit, it will send a message on the serial data line to the remote control door lock receiver (RCDLR) to enter the power door latches in Lock or Unlock status. For more detailed information concerning power door lock operation refer to Power Door Locks Description and Operation .

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • The PDM detects a short to ground in the passenger door lock switch lock or unlock signal circuit.
    • Condition must be present for greater than 30 seconds.

Actions Taken When the DTC Sets

Stores DTC B3145 or B3155 in PDM memory.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

The following conditions may cause an intermittent malfunction:

    • There is an intermittent short to ground in the passenger door lock switch lock or unlock signal circuit.
    • The passenger door lock switch is shorted to ground internally or is sticking.
    • The passenger door lock switch was pressed for longer than 30 seconds.

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

  1. Ignition OFF, disconnect the passenger door lock switch harness connector.
  2. Test for less than 1 ohm of resistance between the ground circuit terminal C and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Door Lock Switch parameter is IDLE.
  5. If not the specified value, test the appropriate door lock switch signal circuit for a short to ground. If the circuit tests normal, replace the PDM.
  6. If all circuits test normal, test or replace the door lock switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Door Lock Switch Replacement - Passenger Front
    •  Control Module References for PDM replacement, setup, and programming