GM Service Manual Online
For 1990-2009 cars only

Object Number: 573265  Size: LF
Theft Deterrent System Components
Theft Deterrent System Schematics
Theft Deterrent System Schematic Icons

Circuit Description

In this mode, the body control module (BCM) will learn the current Passlock™ sensor code value. The following list is the two theft relearn procedures:

    • Scan Tool Relearn Procedure PASSLOCK Reprogramming Seed and Key
    • Auto-Learn Procedure PASSLOCK Reprogramming Auto Learn

Conditions for Setting the DTC

    • A new BCM has been installed and the ignition is turned to the ON position but not rotated to the CRANK position. Once the ignition switch has been rotated to the CRANK position, the BCM will learn the Passlock™ code. The theft relearn procedure will need to be run in order to make the powertrain/vehicle control module (PCM/VCM) receive the correct fuel enable password.
    • The BCM is in the learn mode but does not see a valid Passlock™ sensor code because of a sensor or a wiring problem.

Action Taken When the DTC Sets

The vehicle will not run. The security telltale will be ON.

Conditions for Clearing the MIL/DTC

    • The DTC will clear after an ignition cycle has occurred after the BCM has learned a valid code.
    • Using a scan tool.

Diagnostic Aids

    • Prior to replacing a BCM, ensure that all of the diagnostics have been completed. Refer to Diagnostic Trouble Code (DTC) List/Type .
    • Inspect the Passlock™ sensor harness for intermittent or poor connections. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests for the proper operation of the 12v reference (Security Sensor Power) circuit, sensor ground circuit, and passlock™ sensor signal (data) circuit. Troubleshoot the appropriate DTC prior to diagnosing DTC B3031.

Step

Action

Value(s)

Yes

No

1

Did you perform the Theft Deterrent (VTD) Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Install a scan tool.
  2. Momentarily rotate the ignition switch to CRANK (do not start the vehicle).
  3. Release the ignition switch to ON.
  4. Select the body control module display DTCs function on the scan tool.

Does the scan tool display DTC B3031 as a current DTC?

--

Go to Step 3

Go to Step 4

3

Does the scan tool display DTC [B2947, B2948, B2957, B2958, or B3033]?

--

Go to Diagnostic Trouble Code (DTC) List/Type

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition
  3. Start the vehicle.
  4. Select the body control module display DTCs function on the scan tool.

Does the DTC reset?

--

Go to Step 3

System OK