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 P1626: Theft Deterrent Fuel Enable Signal Lost

### Circuit/System Description

The body control module (BCM) produces the theft deterrent fuel enable signal when the ignition is ON and the proper ignition code voltage value is detected. The engine control module (ECM) monitors the fuel enable signal during crank. If the proper signal is present on the class 2 serial data circuit, the ECM enables fuel delivery in order to allow the engine to start. If the ECM determines that the fuel enable signal is not present or incorrect while the engine is running, DTC P1626 is set. The engine continues to start and run as long as DTC P1626 is stored.

### Conditions for Running the DTC

The engine is running.

### Conditions for Setting the DTC

The ECM has detected a loss of the state of health serial data message from the Theft Deterrent System.

### Action Taken When the DTC Sets

• | The ECM will not illuminate the malfunction indicator lamp (MIL).

• | The ECM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

### Conditions for Clearing the DTC

• | A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• | The DTC can be cleared by using a scan tool.

### Diagnostic Aids

A new replacement ECM will be in a functional state to learn the password from the BCM. If the BCM is replaced, the ECM must be placed in password learning mode to relearn a new password. Once learned, the password becomes permanent information that remains with the vehicle. The loss of ECM battery or ignition voltage will not affect the programmed password information.

### 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

Important: DTC P1626 can only be set along with a corresponding theft deterrent B-code. Refer to the DTC list in order to diagnose the appropriate theft deterrent B-code.

Proceed to diagnose the existing B-code(s). Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming