P0633

DTC P0633

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC P0633
- Theft Deterrent Key Not Programmed

Circuit/System Description

When learning the fuel enable 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 the learn mode will be exited and the DTC cleared. The learn procedure consists of the following steps:

* Complete the 10 minute immobilizer relearn procedure
* Turn the ignition to "OFF" for 5 seconds
* Turn the ignition to "RUN" and wait 10 seconds. If this vehicle is equipped with a manual transmission perform the clutch position sensor learn, if required.
* Turn the ignition to "OFF" for 5 seconds
* Turn the ignition to "RUN" then crank and run engine
* ECM issues challenge to immobilizer/immobilizer responds correctly (will occur within 5-10 seconds of vehicle starting)

If the ECM does not complete all of the steps above it will not exit the learn mode, P0633 will remain current and indicate a fault.

If the ECM does not exit learn mode, P0633 will remain current and indicate a fault.

Conditions for Running the DTC

Theft deterrent system is activated.

Conditions for Setting the DTC

DTC P0633 will set any time the ECM enters learn mode.

Action Taken When the DTC Sets

DTC P0633 is type C DTC.

Conditions for Clearing the DTC

DTC P0633 is type C DTC.

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.

For a successful communication/learn the ECM (high speed) and theft deterrent module (TDM) (low speed) must communicate. Because of different communication busses (high and low speed) the IPC acts as a buffer between the ECM and TDM. If this DTC cannot clear, using the scan tool, confirm communication between the TDM and the IPC.

* If the fuel gauge is working the IPC and ECM are communicating.
* Check the TDM for history codes, which indicates a learn mode was entered.
* A P0633 will not prevent the engine from cranking. If engine does not crank, start or run, look for causes independent of the P0633.

Reference Information
Schematic Reference

Immobilizer Schematics (Immobilizer Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Immobilizer Description and Operation (Immobilizer)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Note: 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 (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, look for communication issues before replacing any modules.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for ECM replacement, setup, and programming