DTC Descriptor
DTC P0633 : Theft Deterrent Key Not ProgrammedDiagnostic Fault Information
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
When learning the pre-release password, 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 password and challenge/response are learned, learn mode will be exited when the engine is successfully started. At this point, the DTC will be cleared. If the ECM does not exit learn mode, 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 will illuminate.
Conditions for Clearing the DTC
| • | A current DTC P0633 will be cleared upon a successful engine start signaling the exit of learn mode. |
| • | 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 "key" referenced in the DTC descriptor does not refer to the vehicle key. In this case, "key" is referring to the challenge response.
DTC P0633 requires a successful engine start to exit the learn procedure and clear the DTC. If an unrelated malfunction exists that causes engine starting to be disabled or otherwise unavailable, learn mode will not exit and DTC P0633 will remain current. In this situation, the cause of the inoperative engine starting must be corrected before diagnosing DTC P0633.
Reference Information
Schematic Reference
Theft Deterrent System Schematics
Connector End View Reference
Theft Deterrent System Connector End Views
Description and Operation
Vehicle Theft Deterrent (VTD) 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.
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.- Ignition in the CRANK position, verify the scan tool Ignition Run/Crank parameter is Active.
- Perform the Programming Theft Deterrent System Components procedure. Refer to Programming Theft Deterrent System Components . The vehicle should start, the ECM should exit learn mode, and DTC P0633 should clear.
| ⇒ | If not the specified value, refer to Power Mode Mismatch . |
| ⇒ | 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.
