DTC P1629
DTC P1629 |
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 |
DTC P1629
Immobilizer Fuel Enable Signal Not Received
Circuit/System Description |
The body control module (BCM) sends the prerelease password 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.
Conditions for Running the DTC |
Ignition is in the Accessory or Run position.
Conditions for Setting the DTC |
The ECM receives an incorrect prerelease password from the BCM.
Action Taken When the DTC Sets |
• |
The security indicator in the instrument cluster will be illuminated.
|
• |
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 or when a scan tool is used to clear DTCs.
|
Reference Information |
Schematic Reference
Immobilizer Schematics
Connector End View Reference
Component Connector End Views
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 | ||
Because of normal system communications between the BCM and ECM, any immobilizer B-codes must be diagnosed prior to the diagnosis of P-codes. |
Perform the Immobilizer Relearn procedure. Refer to Immobilizer System Component Programming . The ECM should successfully complete the password learn and the vehicle should start.
Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming