Circuit Description
The BCM provides the steering column control function which allows the column to be electronically locked or unlocked. The BCM can provide a ground or battery output on the column lock/unlock drive (A) circuit (CKT 1603) depending on the desired steering column motor position. The BCM controls the position of the motor based on input information, including the ignition position, the key-in-ignition status, and the system voltage, and information sent from the steering column feedback switch, the PASS®-Key system, and the PCM. The BCM uses the feedback switch in order to monitor the motor position and determine if the commanded position was accomplished. The BCM also monitors its internal circuitry for the column lock/unlock drive (A) circuit. If the BCM detects an internal malfunction, a malfunction is present and a DTC will set.
Conditions for Setting the DTC
| • | The BCM detects an internal malfunction (an open or a short to voltage) in the column lock/unlock drive (A) circuit. |
| • | There is an open in the BCM ground CKT 150. |
| • | The condition must be present for 100 ms. |
Action Taken When the DTC Sets
| • | Stores a DTC B2588 in the BCM memory. |
| • | Sends a message to the IPC to display the SERVICE COLUMN LOCK message. |
Conditions for Clearing the DTC
| • | The BCM no longer detects an internal malfunction (an open or a short to voltage) in the column lock/unlock drive (A) circuit. |
| • | There is no longer an open in the BCM ground CKT 150. |
| • | A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | Use the IPC clearing DTCs feature. |
| • | Use a scan tool. |
Diagnostic Aids
| • | The BCM grounds the steering column lock/unlock motor through CKT 150. If the BCM is unable to ground steering column lock/unlock motor through CKT 150, the BCM will set a DTC 2588. |
| • | Disconnecting the steering column connector C207 with the ignition in the ON position will cause the BCM to enter a fail enable mode. The steering column will remain inoperative until the fail enable mode is cleared. To clear this mode, disconnect the BCM fuse #25 for 15 seconds. |
| • | If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This test will for an open in the BCM ground CKT 150.
-
This test will check CKT 150 for an intermittent malfunction or poor connections.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Were you sent here from the BCM Diagnostic System Check? | -- | ||
Is the test light ON? | -- | |||
3 | Locate and repair open in CKT 150. Is the circuit repair complete? | -- | -- | |
Check the BCM connector C3 terminal A2 for an intermittent malfunction. Refer to Diagnostic Aids. Was an intermittent malfunction found and repaired? | -- | |||
5 |
Is the replacement complete? | -- | -- | |
6 |
Are all DTCs cleared? | -- | -- |
