Circuit Description
The body control module (BCM) sends fuel enable password to the powertrain control module (PCM) via the serial data circuit when the ignition is ON and the BCM has read a learned transponder value from the key. The PCM verifies the fuel enable password to the fuel enable password stored in memory. If the fuel enable password is correct, the PCM enables starting and fuel delivery systems. When replacing a PCM with a GM SPO replacement part, the new PCM will learn the incoming fuel enable password immediately upon receipt. DTC P1630 is an informational code indicating the PCM is ready to learn the fuel enable password.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1630 Theft Deterrent Learn Mode Active
Conditions for Running the DTC
The ignition is switched to CRANK then to ON.
Conditions for Setting the DTC
The PCM remains in the password learn mode for more than 2 seconds.
Action Taken When the DTC Sets
| • | The vehicle will start. |
| • | The drivers information center displays Theft System Not Programmed message. |
| • | The PCM will not illuminate the malfunction indicator lamp (MIL). |
Conditions for Clearing the MIL/DTC
| • | The PCM clears the current status of the DTC when it learns the fuel enable password from the BCM. |
| • | A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
A GM SPO replacement PCM is in a functional state to learn the fuel enable password from the BCM. If the BCM is replaced, the PCM must be placed in the password learning mode to relearn the new fuel enable password from the BCM. The loss of PCM battery or ignition voltage does not affect the programmed password information. Refer to Immobilizer System Component Programming .
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Immobilizer Schematics Connector End View Reference: Immobilizer Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | ||
