P1631

Circuit Description
This test checks for mismatched passwords between the Vehicle Theft Deterrent (VTD) control module and Powertrain Control Module (PCM). Whenever the VTD control module or PCM are replaced, a theft learn procedure must be followed in order for the new password to be learned.

Conditions for Running the DTC
The vehicle Anti-Theft system is enabled.

Conditions for Setting the DTC
^ The fuel disable is set.
^ An incorrect fuel continue password has been received.

Action Taken When the DTC Sets
^ The vehicle will not start.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.

Conditions for Clearing the MIL/DTC
^ The PCM will turn the MIL off after three consecutive trips without a fault condition.
^ A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures
^ The use of a scan tool.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
3. The 11 minute and 30 second time criteria, are minimum required amounts of time. Exceeding these limits will not interfere with the Auto Learn Procedure. A scan tool can be used (VTD Auto Learn Timer equals Inactive) to determine when the 11 minutes have expired.
8. If DTC P1631 is set, the Re-Learn procedure was not performed correctly. The Re-learn procedure will then have to be repeated.