For 1990-2009 cars only
Circuit Description
This diagnostic tests for the Enable Password Learning Flag indicating the PCM is in learn password mode. This mode allows the PCM to learn the password from the body control module (BCM) at assembly or when serviced. The password needs to be learned whenever the PCM or the BCM is replaced or if a replacement ignition key that has a different resistance is used.
Conditions for Running the DTC
The PCM is ready to learn a new password from the BCM.
Conditions for Setting the DTC
The BCM is not sending a valid password or not sending a password at all.
Action Taken When the DTC Sets
| • | The engine starts and stalls when the BCM detects a theft mode. |
| • | The engine starts and stalls when the PCM losses communication with the BCM. |
| • | The engine operates normally, but an internal BCM failure has occurred. |
| • | The PCM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM records the operating conditions at the time during which the diagnostic fails. The PCM stores this information in the Failure Records. |
Conditions for Clearing the DTC
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Use a scan tool in order to clear the DTC. |
Diagnostic Aids
| • | A DTC 1630 is a code used at the assembly plant, dealership, or repair facility which indicates that the system has enabled the learn mode. This means that the PCM is now ready to learn a new password from the BCM. This DTC sets because the BCM never sent a valid password to the PCM while in the learn mode. When this occurs, the vehicle is vulnerable to vehicle theft. |
| • | For an intermittent condition, refer to Symptoms . |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Diagnostic System Check - Body Control System in Body Control System |
