Test Description

The numbers below refer to the step numbers on the diagnostic table. See Fig 1.

1. 2
   
   This DTC may set as a result of other Passlock System problems. Diagnose any BCM DTCs prior to continuing with this diagnostic.
2. 3
   
   A DTC B3031 may set in the body control module (BCM) during the Password Learn Procedure.
Fig 1: DTC P1631 Diagnostic Table (Steps 1-4)
Courtesy of GENERAL MOTORS CORP.