GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 Express 🢒 Body and Accessories 🢒 Theft Deterrent 🢒 DTC B0688

Circuit Description

The security indicator is a hardwired lamp to the instrument panel cluster (IPC) and controlled by the passlock module. The lamp receives ignition voltage form the gages fuse.

Conditions for Setting the DTC
    • The ignition switch is ON.
    • The Passlock™ module is unable to provide a complete path to ground for the security indicator due to a wiring fault or a defective Passlock™ module.

Action Taken When the DTC Sets
    • The security indicator will be ON.
    • The security indicator may be ON when the ignition switch is OFF if the security indicator control circuit is shorted to battery.

Conditions for Clearing the MIL/DTC
    • The current DTC will clear after an ignition cycle occurs without the fault recurring.
    • The Passlock module history DTCs clear after 100 ignition cycles with no current codes active.
    • Using a scan tool.

Diagnostic Aids
    • Perform a visual inspection of the wiring and the connectors.
    • Inspect the harness for an intermittent or a short to battery. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the numbers on the diagnostic table:

  1. This step verifies the DTC is not intermittent.

    2.

  2. This step isolates the problem between the instrument cluster and the harness.

Step

Action

Yes

No

1

Did you perform the Theft Deterrent Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Install a scan tool.
  2. Turn ON the ignition with the engine OFF.
  3. With a scan tool, command the security indicator on and off.

Does the security indicator change states with each command?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the Passlock™ module connector.
  3. Turn the ignition ON with the engine OFF.

Is the security indicator illuminated?

Go to Step 4

Go to Step 5

4

Test the security indicator signal circuit of the Passlock™ module 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 9

Go to Step 6

5

Inspect for poor connections at the harness connector of the passlock 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 9

Go to Step 8

6

Inspect for poor connections at the harness connector of the instrument panel cluster. 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 9

Go to Step 7

7

Replace the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 9

--

8

Important: When replacing the passlock module refer to Theft Deterrent Module Replacement .

Replace the passlock module. Refer to Theft Deterrent Module Replacement .

Is the repair complete?

Go to Step 9

--

9
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle under the conditions for running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK