For 1990-2009 cars only
DTC P1631 Theft Deterrent Start Enable Signal Not Correct for Cadillac DeVille 1999
Circuit Description
This test checks for mismatched passwords between the IPC and PCM. Whenever the IPC or PCM are replaced, a theft learn procedure must be followed in order for the new password to be learned.
Conditions for Running the DTC
Vehicle Anti-Theft system enabled.
Conditions for Setting the DTC
| • | Fuel disable lockout set. |
| • | An incorrect fuel continue password has been received. |
Action Taken When the DTC Sets
| • | The Malfunction Indicator Lamp (MIL) will not illuminate. |
| • | No message will be displayed. |
Conditions for Clearing the DTC
| • | A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test. |
| • | A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail. |
| • | Use a scan tool to clear DTCs. |
| • | Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module Description . |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Refer to PCM programming proceedures |
