• | 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 and overview of each diagnostic category. |
The theft deterrent module (TDM) sends the fuel enable password to the engine control module (ECM) via the serial data circuit. If the password sent by the TDM equals the password stored in the ECM, the ECM will allow vehicle starting.
Ignition is in the RUN position.
The fuel enable password is valid but does not pass authentication in the ECM.
• | The security indicator will illuminate. |
• | Vehicle starting will be disabled. |
• | A current DTC P1632 will be when a valid password is received. |
• | A history DTC will be cleared after 40 malfunction-free ignition cycles or when a scan tool is used to clear DTCs. |
Immobilizer Connector End Views
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 Programming Theft Deterrent System Components procedure. 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming