GM Service Manual Online
For 1990-2009 cars only

Circuit 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 .

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B3145 Right Front/Passenger Unlock Switch Circuit Low
    • DTC B3155 Right Front/Passenger Lock Switch Circuit Low

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 circuits.
    • Condition must be present for greater than 20 seconds.

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 circuits.
    • The passenger door lock switch is shorted to ground internally or is sticking.
    • The passenger door lock switch was pressed for longer than 20 seconds.
    • Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics and Door Control Module Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn OFF the ignition.
  2. Disconnect the passenger door switch.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.
  5. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 3

Go to Step 4

3

Test the appropriate passenger door lock switch signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 5

4

Inspect for poor connections at the harness connector of the passenger door lock switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

5

Inspect for poor connections at the harness connector of the passenger door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

6

Replace the passenger door lock switch. Refer to Door Lock Switch Replacement - Passenger Front .

Did you complete the replacement?

Go to Step 8

--

7

Replace the passenger door module (PDM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

Go to Step 8

--

8

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK