Test Description

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

1. 1
   
   The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the fault occurred. The scan tool stores this data for later reference.
2. 2
   
   The PCM may not have learned the new password. Refer to Password Learn Procedure portion of the service manual.
3. 4
   
   The scan tool can display whether or not the BCM has received and learned the password from the lock cylinder. If the password is not received, the reason the PCM set this DTC may be due to a password that has not yet been learned due to a component being replaced or a problem in the BCM or a VTD component.
4. 5
   
   Replacement VCMs/PCMs must be reprogrammed. A reprogrammed PCM does not require the password learn procedure to be performed. The password will be learned on the first ignition cycle.
5. 6
   
   A Passlock™ theft deterrent, or BCM DTC being set indicates that a Passlock™ component may be malfunctioning.
6. 7
   
   If no DTCs were set and the BCM has not learned (received) a password from the ignition lock cylinder, the BCM may need to learn the password, or may be malfunctioning.
7. 9
   
   If no malfunctions are present at this point and no additional DTCs were set, refer to Diagnostic. Aids for additional checks and information.

Fig 1: DTC P1632 Diagnostic Table (Steps 1-9)

Courtesy of GENERAL MOTORS CORP.