P1629
DTC P1629
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 P1629
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Immobilizer Fuel Enable Signal Not Received
Circuit/System Description
The body control module (BCM) sends the pre-release information to the engine control module (ECM) via the serial data circuit. The ECM then sends a challenge to the BCM. Both the ECM and BCM perform a calculation on this challenge. If the calculated response from the BCM equals the calculation performed by the ECM, the ECM will allow vehicle starting. The BCM follows this action by sending the remaining immobilizer data, referred to as the fuel enable or fuel continue signal, to the ECM. If the immobilizer data sent by the BCM matches that stored by the ECM, the ECM will allow the engine to remain running.
Conditions for Running the DTC
Ignition is in the ACCESSORY or RUN position.
Conditions for Setting the DTC
The ECM does not receive a correct fuel enable password from the BCM.
Action Taken When the DTC Sets
* The security indicator in the instrument cluster will illuminate.
* Vehicle starting will be disabled.
Conditions for Clearing the DTC
* A current DTC P1629 will be cleared when a correct fuel enable password is received.
* A history DTC will be cleared after 40 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Immobilizer Schematics Immobilizer Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
Description and Operation
Immobilizer Description and Operation (with BTM) Immobilizer Description and Operation (with BTM)Immobilizer Description and Operation (without BTM) Immobilizer Description and Operation (without BTM)
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 Control Module References for scan tool information
Circuit/System Verification
1. Verify there are no immobilizer DTCs set in the BCM.
• If any immobilizer DTCs are set in the BCM
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If no immobilizer DTCs are set in the BCM
2. Perform the BCM immobilizer learn using the Body Control Module IMMO Function with Existing Transponder or Remote Key in SPS. Refer to Immobilizer System Component Programming (without BTM) Immobilizer System Component Programming (without BTM)Immobilizer System Component Programming (with BTM) Immobilizer System Component Programming (with BTM).
3. Verify the BCM successfully completes the learn procedure and the engine starts.
• If the BCM does not successfully learn or the engine does not start
Perform the ECM immobilizer learn using the Engine Control Module IMMO Learn in SPS. Refer to Immobilizer System Component Programming (without BTM) Immobilizer System Component Programming (without BTM)Immobilizer System Component Programming (with BTM) Immobilizer System Component Programming (with BTM).
• If the vehicle starts
4. All OK
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Control Module References for ECM replacement, setup and programming