P1629

DTC P1629

CIRCUIT DESCRIPTION
The theft deterrent control module sends the fuel enable password to the engine control module (ECM) via the serial data circuit. The ECM verifies the fuel enable password received matches the password stored in memory. If the fuel enable password is correct, the ECM enables the starting and fuel delivery systems. When replacing a ECM with a GM SPO replacement part, the new ECM will learn the incoming fuel enable password immediately upon receipt.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The engine control module (ECM) has not received the fuel enable password from the theft deterrent control module within 1 second.

ACTIONS TAKEN WHEN THE DTC SETS
- The vehicle will not start.
- The instrument panel cluster (IPC) will illuminate the SECURITY indicator.
- The ECM will not illuminate the malfunction indicator lamp (MIL).

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 a scan tool.

DIAGNOSTIC AIDS
A GM SPO replacement engine control module (ECM) is in a functional state to learn the password from the theft deterrent control module. If the theft deterrent control module is replaced, the ECM must be placed in password learning mode to relearn the new password. Once learned, the password becomes permanent information that remains in the ECM. The loss of ECM battery or ignition voltage does not affect the programmed password information. Refer to Programming Theft Deterrent System Components.

TEST DESCRIPTION

Steps 1-4:

Steps 5-6:

The numbers below refer to the step numbers on the diagnostic table.
2. Verifies if the condition for setting DTC B3060 is current.
3. To set this code, the password that the ECM has learned does not agree with the password being received from the theft deterrent control module or the ECM did not received the password from the theft deterrent control module. This condition can occur if the theft deterrent control module has been replaced and the Programming Theft Deterrent System Components procedure has not been performed.
5. If the ECM resets the DTC after the programming theft deterrent system components procedure has been performed, the theft deterrent control module is malfunctioning.