Circuit Description
The vehicle theft deterrent system (VTD) is incorporated within the body control module (BCM). If the BCM has been replaced, the password must be relearned. If the engine control module (ECM) is replaced, the replacement ECM should learn the password within a few seconds after the ignition is turned ON. This is an information code indicating that the ECM is ready to learn the VTD password.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1630 Theft Deterrent Learn Mode Active
Conditions for Running the DTC
| • | The VTD system has allowed fuel delivery. |
| • | The ECM is in the theft deterrent password learn mode. |
Conditions for Setting the DTC
The ECM remains in theft deterrent password learn mode for more than 2 seconds.
Action Taken When the DTC Sets
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
| • | The ECM will store conditions which were present when the DTC set as failure records data only. This information will not be stores as freeze frame data. |
Conditions for Clearing the DTC/MIL
| • | 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 new replacement ECM will be in a functional state to learn the password from the BCM. If the BCM is replaced, the ECM 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 ECM battery or ignition voltage will not affect the programmed password information.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Immobilizer Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | ||
