GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Envoy - 4WD 🢒 DTC 🢒 DTC B3033 Security System Indicates Tamper

Object Number: 381577 Size: LF
Theft Deterrent System Components
Theft Deterrent System Schematics
Theft Deterrent System Schematic Icons

Circuit Description

The body control module (BCM) will read an analog voltage from the Passlock sensor. Based on the Passlock internal reference, the BCM will determine if the indicated voltage is 1 of the following conditions:

    • Open
    • Shorted to ground
    • A valid code
    • A tamper code

In the case of a tamper code the BCM is reading a tamper code.

Conditions for Setting the DTC
    • The BCM will inspect for a tamper code when the ignition switch rotates from ON to CRANK.
    • The BCM is reading a tamper code from the Passlock sensor for longer than 1.0 seconds.

Action Taken When the DTC Sets
    • The vehicle will not run. The security telltale will be flashing.
    • The Passlock state is Tamper.

Conditions for Clearing the DTC
    • The DTC will clear once an ignition cycle occurs without the fault recurring.
    • The BCM history codes will clear after 100  ignition cycles occur without the fault recurring.
    • Use a scan tool.

Diagnostic Aids
    • Prior to replacing a BCM, ensure that all of the diagnostics have been completed. Refer to Body Control Module Replacement 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 in Wiring Systems.
    • The VTD internal diagnostics are not run while the tamper timer is active.

Test Description

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

  1. This step determines if DTC B3033 is intermittent.

    2.

  2. This step inspects for a mechanical problem.

    3.

  3. Replace the Passlock sensor. This sensor is the only component able to produce the voltage window necessary in order to set DTC B3033.

Step

Action

Value(s)

Yes

No

1

Did you perform the VTD Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Turn the ignition switch to the ON position.
  2. Use a scan tool in order to clear the Passlock DTCs.

Did DTC B3033 clear?

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Go to Intermittents and Poor Connections

Go to Step 3

3

Inspect the key switch mechanical assembly.

Is there binding or has the cylinder magnet been damaged?

--

Go to Step 4

Go to Step 5

4
  1. Replace the ignition lock cylinder in the Lock Housing assembly.
    2. • With tilt wheel steering, refer to Ignition Lock Cylinder Replacement - On Vehicle in Steering.
    • With standard wheel steering, refer to Ignition Lock Cylinder Replacement - On Vehicle in Steering
  2. Perform one of the following Passlock learn procedures:

Is the repair complete?

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Go to Diagnostic System Check - Theft Deterrent

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5

  1. Replace the Passlock Sensor.
    2. • To disassemble Lock Housing:
    • To reassemble Lock Housing:
  2. Perform one of the following Passlock learn procedures:

Is the repair complete?

--

Go to Step 7

Go to Step 6

6

Replace the body control module. Refer to Body Control Module Replacement in Body Control Systems.

Is the repair complete?

--

Go to Step 7

--

7
  1. Reconnect all of the previously disconnected connectors and components.
  2. Turn the ignition switch to the ON position.
  3. Connect the scan tool.
  4. Clear the DTCs.
  5. Perform one of the following Relearn Procedures:
    6. • Seed and Key in 10 minutes PASSLOCK Reprogramming Seed and Key
    • Auto Learn in 30 minutes PASSLOCK Reprogramming Auto Learn

Is the operation complete?

--

Go to Diagnostic System Check - Theft Deterrent

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