Circuit Description
When a body control module (BCM) is replaced, it must be programmed to accept the analog voltage signal code of the existing Passlock™ sensor. When the BCM is replaced, the service replacement BCM is programmed to accept the first Passlock™ code it detects. If the BCM is unable to detect a valid Passlock™ code, the BCM will never end the programming sequence and DTC B3031 will continue to be set as current.
In this mode, the BCM will learn the current Passlock™ sensor code value.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3031 Security System Controller In Learn Mode
Conditions for Setting the DTC
| • | A new BCM has been installed and the ignition is turned to the ON position but not rotated to the CRANK position. Once the ignition switch has been rotated to the CRANK position, the BCM will learn the Passlock™ code. The theft relearn procedure will need to be run in order to make the engine control module (ECM) receive the correct fuel enable password. |
| • | The BCM is in the learn mode but does not see a valid Passlock™ sensor code because of a sensor or a wiring problem. |
Action Taken When the DTC Sets
| • | The BCM stores DTC B3031 in the BCM memory as a current DTC. |
| • | The BCM sends a message to the instrument cluster to turn ON the SECURITY indicator. |
Conditions for Clearing the DTC
| • | A current DTC B3031 changes to history when the BCM detects a valid Passlock™ sensor code. |
| • | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Diagnostic Aids
| • | If there is an open or short in any of the Passlock™ sensor circuits, the BCM will be unable to read a valid code from the Passlock™ sensor when the program mode is active. |
| • | Always diagnose all other Passlock™ DTCs first before diagnosing this DTC. These DTCs will affect the BCM's ability to properly read a Passlock™ code. |
| • | If DTC B3031 is set in the BCM as a history DTC, clear the DTC and recheck the system. A history DTC B3031 indicates that the BCM has successfully completed the programming mode. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Theft Deterrent System Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the scan tool display DTC B3031 as a current DTC? | Go to Step 3 | Go to Step 4 |
Does the scan tool display DTC B2957 or B2958? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
4 | Perform the Programming Theft Deterrent System Components procedure. Is DTC B3031 still set as current? | Go to Step 5 | Go to Step 7 |
5 | Inspect for poor connections at the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 6 |
6 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 7 | -- |
7 |
Does the DTC reset? | Go to Step 3 | System OK |
