Circuit Description
The Vehicle Theft Deterrent (VTD) System is incorporated within the remote control door lock receiver (RCDLR). If the RCDLR has been replaced, the password must be relearned by the engine control module (ECM). If the 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 ignition is ON.
Conditions for Setting the DTC
The engine control module (ECM) remains in theft deterrent password learn mode for more than 2 seconds.
Action Taken When the DTC Sets
| • | The ECM sends a serial data message to the instrument panel cluster (IPC) to illuminate the SECURITY indicator. |
| • | The ECM will not illuminate the malfunction indicator lamp (MIL). |
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 GM SPO replacement ECM is in a functional state to learn the password from the RCDLR. If the RCDLR 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 .
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
