GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy C Silverado - 2WD 🢒 DTC 🢒 DTC B3031 Security System Controller in Learn Mode

Object Number: 381660 Size: LF
Theft Deterrent System Components
Theft Deterrent System Schematics
Handling ESD Sensitive Parts Notice

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
    • Auto-Learn Procedure

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 control module (PCM) 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) Displaying in Body Control Systems.
    • Perform a visual inspection of the wiring and the connectors.
    • Inspect the Passlock sensor harness for intermittent or poor connections. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Test Description

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

  1. If a problem exists in CKT 812, CKT 1836, or CKT 1057, troubleshoot the appropriate DTC prior to diagnosing DTC B3031.

Step

Action

Value(s)

Yes

No

1

Did you perform the VTD System Check?

--

Go to Step 2

Go to Vehicle Theft Deterrent (VTD) System Check

2

Check for the following DTCs:

    • B2947
    • B2948
    • B2957
    • B2958

Are 1 or more of the DTCs set?

--

Go to the appropriate DTC Table

Go to Step 3

3
  1. Replace the Passlock sensor. Refer to Theft Deterrent System Components
  2. Perform the Theft Relearn Procedure. Refer to PASSLOCK Reprogramming Auto Learn .

Is the repair complete?

--

Go to Step 5

Go to Step 4

4

Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

Go to Step 5

--

5
  1. Reconnect all of the previously disconnected connectors and the components.
  2. Turn the ignition switch to the ON position.
  3. Connect the scan tool.
  4. Clear the DTCs.
  5. Perform the Theft Relearn Procedure. Refer to PASSLOCK Reprogramming Auto Learn .

Is the operation complete?

--

Go to Vehicle Theft Deterrent (VTD) System Check

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