For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B3033: Security System Indicates Tamper

### Circuit/System Description

The Passlock™ System is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock™ controller reads the coded Passlock™ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock™ assembly and the Passlock™ controller. If the data is correct, indicating rotation of the lock cylinder with the proper mechanically cut key, the Passlock™ controller sends a password to the powertrain controller via serial data to indicate that engine starting should be allowed. The Passlock™ controller also interfaces with the driver displays subsystem to indicate, via the security indicator, the Passlock™ subsystem status and acute subsystem failures.

### Conditions for Setting the DTC

• | The analog voltage signal sampled at the body control module (BCM) Passlock™ detection circuit is a tamper signal indicating a Passlock™ tamper.

• | The condition must be present during an engine start attempt.

### Action Taken When the DTC Sets

When attempting to start the engine and the Passlock™ sensor sends a tamper signal, the BCM will take one of two actions:

• | If the BCM programming mode is not active AND the BCM is not in fail enable mode, then:

- | The BCM stores DTC B3033 in memory.

- | The BCM sends a message to the instrument cluster to flash the SECURITY indicator.

- | The BCM sends a message to the ECM via serial data to disable engine operation.

- | The BCM disables sampling of the Passlock™ sensor analog voltage signal for a time-out period of 10 minutes.

- | If the ignition switch is left on for at least 10 minutes, the BCM enters the theft deterrent re-learn mode.

• | If the BCM programming mode is active AND the BCM is in fail enable mode, then:

- | The BCM stores DTC B3033 in memory.

- | The BCM sends a message to the instrument cluster to turn on the SECURITY indicator.

- | The BCM will send a message to the ECM via serial data to allow the engine to start.

### Conditions for Clearing the DTC

• | A current DTC B3033 clears when the BCM detects a valid Passlock™ sensor code.

• | When the BCM detects a valid code from the Passlock™ sensor, the ignition switch must be cycled from OFF to ON before this DTC can change from a current DTC to a history DTC.

• | A history DTC clears after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

### Diagnostic Aids

• | A malfunctioning Passlock™ sensor may cause an intermittent malfunction to occur.

• | If the SECURITY indicator is flashing, the BCMs Passlock™ has entered a vehicle disable state that will last approximately 10 minutes. Disconnecting the battery will not clear the timer sequence, it will resume when battery power is restored. Even if a proper Passlock™ sensor code is read during the vehicle disable period, the vehicle will not start until the 10 minute time period has elapsed. After this 10 minute time period, the SECURITY indicator will change from a flashing state to a solid on state. At this time, the BCM enters the theft deterrent re-learn mode. The engine will start if the BCM detects the correct Passlock™ sensor code.

• | Check for poor connections at both the BCM and the ignition lock cylinder assembly which could cause an open, incorrect Passlock™ sensor voltage signal, or intermittent malfunction.

### Reference Information

#### Schematic Reference

Immobilizer Schematics

#### Connector End View Reference

Master Electrical Component List

#### Description and Operation

Immobilizer Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Testing

1. Install the scan tool. Attempt to CRANK but do not start the vehicle and release the ignition switch to ON. Verify DTC B3033 is set as current.

⇒ | Inspect the area around the ignition lock cylinder for any device which could create a magnetic field, audio speaker, magnet, etc. Remove device and check for DTC B3033 as current.

2. If DTC B3033 is current a problem exists with the Passlock™ sensor and/or the wiring harness.

⇒ | Inspect for poor connections at the Passlock™ sensor. Make the appropriate repair.

⇒ | Replace the ignition and start switch. Refer to Repair Instructions.

3. Perform the Programming Theft Deterrent System Components procedure.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Ignition and Start Switch Replacement

• | Control Module References for BCM replacement, setup, and programming