For 1990-2009 cars

### Circuit Description

The theft deterrent control module produces the theft deterrent fuel enable signal when ignition is ON and the proper transponder key value is detected. The powertrain control module (PCM) monitors the fuel enable signal during crank. If the proper signal is present on the Class 2 Serial Data Circuit, the PCM enables the fuel delivery in order to allow the engine to start. If the PCM is replaced, the replacement PCM should learn the password within a few seconds after the ignition is turned ON. DTC P1630 is an information code indicating that the PCM is ready to learn the theft deterrent password. The engine starts and continues to run with DTC P1630 set.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

The powertrain control module (PCM) remains in theft deterrent password learn mode for more than 2 seconds.

### Actions Taken When the DTC Sets

• | The vehicle will not start.

• | The theft deterrent control module sends a message via the serial data circuit to the instrument cluster to illuminate the SECURITY indicator.

• | The instrument cluster displays STARTING DISABLED and REMOVE KEY message.

• | The powertrain control module (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 a scan tool.

### Diagnostic Aids

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

Step | Action | Yes | No
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Schematic Reference: Theft Deterrent System Schematics Connector End View Reference: Theft Deterrent System Connector End Views
1 | Did you perform the Theft Deterrent Diagnostic System Check? | Go to Programming Theft Deterrent System Components | Go to Diagnostic System Check - Theft Deterrent