GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC sets when the PCM has received Fuel Disable or Fuel Undecided Passwords from the Vehicle Theft Deterrent controller. It is set as a service tool to indicate the VTD is not allowing fuel due to a possible theft attempt or a worn or incorrect ignition key.

Conditions for Setting the DTC

Test Condition

Vehicle Theft Deterrent system enabled.

Failure Condition

Fuel disable password received.

Action Taken When the DTC Sets

    •  The Malfunction Indicator Lamp (MIL) will not illuminate.
    •  No message will be displayed.

Conditions for Clearing the DTC

    •  A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
    •  A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
    • Use a scan tool to clear DTCs.
    • Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation.

Diagnostic Aids

If DTC P1632 is set the IPC has received the incorrect resistance value or an unrecognizable resistance value from the Ignition Key.

Check: the Ignition Key to make sure that it is the correct key for that vehicle and it is clean and dry.

Wait 10 minutes between attempts to clean and retry key.

This DTC may also set if a theft was attempted.

Refer to Section 8 for Vehicle Theft Deterrent procedures.

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

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Refer to Diagnostic Aids

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