DTC P0633

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 Immobilizer Key Not Programmed Circuit/System Description When learning the immobilizer data, as well as the challenge and response sequence, the engine control module (ECM) is placed in learn mode. DTC P0633 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the immobilizer data and challenge/response are learned, learn mode will be exited when the engine is successfully started. If the ECM does not exit learn mode, DTC P0633 will remain current and indicate a fault. Conditions for Running the DTC The ECM is in learn mode. Conditions for Setting the DTC DTC P0633 will set any time the ECM enters learn mode. Action Taken When the DTC Sets The security indicator in the instrument cluster will illuminate. Conditions for Clearing the DTC A current DTC will be cleared upon a successful engine start after exit of learn mode. A history DTC will be cleared after 100 malfunction-free ignition cycles. 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 Control Module References for scan tool information Circuit/System Verification

Note

DTC P0633 will clear upon a successful engine start. Any malfunction that will cause a no- start condition will prevent DTC P0633 from clearing. Prior to diagnosing DTC P0633, ensure that all power moding and engine control systems are operating properly and all conditions that may cause a no-start have been corrected. Do not replace the K20 Engine Control Module. Replacing the K20 Engine Control Module will not correct the no-start condition.

1. Verify there are no immobilizer DTCs set in the K9 Body Control Module. ⇒ If any immobilizer DTCs are set in the K9 Body Control Module Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If no immobilizer DTCs are set in the K9 Body Control Module
2. Perform the K20 Engine Control Module immobilizer learn using the engine control module IMMO Learn in SPS. Refer to Immobilizer System Component Programming.
3. Verify the engine starts after the K20 Engine Control Module completes the learn procedure. ⇒ If the engine does not start An undiagnosed no-start condition exists. Refer to the appropriate subsection and diagnostic to correct the no-start condition. ⇓ If the engine starts
4. All OK.