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: Theft Deterrent Fuel Disable Signal ReceivedCircuit/System Description
The theft deterrent module (TDM) sends the prerelease password to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the TDM. Both the ECM and TDM perform a calculation on this challenge. If the calculated response from the TDM 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 TDM is received by the ECM.
Action Taken When the DTC Sets
| • | The security indicator will illuminate. |
| • | Vehicle starting will be disabled. |
Conditions for Clearing the DTC
| • | A current DTC P1632 will be 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 prerelease password sent to the ECM by the TDM is reliant on the communications between the transponder located in the vehicle key and the TDM. Failure to establish communications or an interruption in the communications between the vehicle key and the TDM will cause the fuel disable message to be sent and the setting of DTC B1632. DTC B3055 or B3060 will be set in the TDM. To properly diagnose DTC P1632, DTC B3055 or B3060 must be diagnosed and corrected first.
Reference Information
Schematic Reference
Connector End View Reference
Immobilizer Connector End Views
Description and Operation
Immobilizer Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Important: Because of normal system communications between the TDM and ECM, any theft deterrent B-codes must be diagnosed prior to the diagnosis of P-codes.
Perform the 10-Minute Immobilizer Relearn procedure. Refer to Immobilizer 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 ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup and programming
