GM Service Manual Online
For 1990-2009 cars only

Refer to Theft Deterrent System in Electrical Diagnosis Section 8A-133.

Circuit Description

DTC P1630 is an information code indicating that the PCM is ready to learn the vehicle theft deterrent password. A replacement PCM should learn the password within a few seconds after the ignition is turned ON. If the PASS-Key® III module has been replaced, the password must be relearned using the Auto Learn Procedure in Theft Deterrent Systems section 9D. The engine will start and continue to run with DTC P1630 set. Refer to Vehicle Theft Deterrent System Section 9D for further information regarding the PASS-Key® III system.

Conditions for Setting the DTC

    • The PASS-Key® III system has allowed fuel delivery.
    • The PCM is in the theft deterrent password learn mode.

Action Taken When the DTC Sets

    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

    • A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear Info function.

Diagnostic Aids

A new replacement PCM will be in a functional state to learn the password from the PASS-Key® III module. If the PASS-Key® III module is replaced, the PCM must be placed in password learning mode to relearn a new password. Once learned, the password becomes permanent information that remains with the vehicle. The loss of PCM battery or ignition voltage will not affect the programmed password information.

Refer to Auto Learn Procedure in Theft Deterrent Systems Section 9D for information concerning the password learning procedure.

DTC P1630 - Theft Deterrent System PCM in Password Learn Mode

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic System Check performed?

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Go to the Auto Learn Procedure in Theft Deterrent Systems Section 9D

Go to the Powertrain On Board Diagnostic (OBD) System Check