Service Information

Cruze

DTC P1632

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 P1632: Immobilizer Fuel Disable Signal Received

The body control module (BCM) sends the pre-release password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the BCM. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting.

Conditions for Running the DTC

Ignition is in the RUN position.

Conditions for Setting the DTC

A fuel disable signal from the BCM is received by the ECM.

Action Taken When the DTC Sets

•	The security indicator in the instrument cluster will illuminate.

•	Vehicle starting will be disabled.

Conditions for Clearing the DTC

•	A current DTC P1632 will be cleared when a valid calculation is received.

•	A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.

Diagnostic Aids

The pre-release password sent to the ECM by the BCM is reliant on the communications between the transponder located in the vehicle key and the BCM. Not be able to establish communications or an interruption in the communications between the vehicle key and the BCM will cause the fuel disable message to be sent and the setting of DTC P1632. DTC B3055 or B3060 will be set in the BCM. To properly diagnose DTC P1632, DTC B3055 or B3060 must be diagnosed and corrected first.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Note: Because of normal system communications between the BCM and ECM, any immobilizer B-codes must be diagnosed prior to the diagnosis of P-codes.

Perform the Immobiliser Relearn procedure. Refer to Immobiliser System Component Programming . The ECM should successfully complete the password learn and the vehicle should start.

⇒	If the ECM does not complete the learn or vehicle starting remains disabled, replace the K20 Engine Control Module (ECM).

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming