GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The SERVICE COLUMN LOCK message is displayed or the steering column does not LOCK or UNLOCK.

1

Did you perform the BCM Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Body Control System

2

Use a scan tool to check for any steering column DTCs stored in the BCM. Refer to Diagnostic Trouble Code (DTC) List/Type in Body Control Systems.

Are any of the following steering column DTCs stored:

    • Is DTC B2587 stored?
    • Is DTC B2588 stored?
    • Is DTC B2592 stored?
    • Is DTC B2593 stored?

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Go to the Diagnostic System Check - Body Control System

Go to Step 3

3

Was the steering column connector C207 disconnected with the ignition switch in the ON position?

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Go to Step 17

Go to Step 4

4

  1. Turn ON the ignition switch.
  2. Use a scan tool to monitor the BCM steering column lock state.

Does the scan tool display steering column lock state as ENABLE STDBY?

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Go to Step 7

Go to Step 5

5

  1. Turn OFF the ignition switch.
  2. Use a scan tool to monitor the BCM key-IN-ignition status with the key IN then OUT of the ignition.

Does the scan tool indicate key-IN-ignition status as ACTIVE with the key IN the ignition and INACTIVE with the key OUT of the ignition?

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Go to Step 6

Go to Key-in-Ignition Chime Inoperative

6

  1. Disconnect the steering column connector C207.
  2. Important: The steering column connector C207 must be disconnected before reading key OUT-of-ignition status.

  3. Use a scan tool to monitor the key-OUT-of-ignition status with the key IN then OUT of the ignition.

Does the scan tool indicate key-OUT-of-ignition status as ACTIVE with the key OUT of the ignition and INACTIVE with the key IN the ignition?

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Go to Step 8

Go to Step 11

7

Connect a test light to B+ and probe terminal A at connector C207 (harness side).

Is the test light ON?

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Go to Step 9

Go to Step 10

8

  1. Turn OFF the ignition switch.
  2. Remove the ignition key OUT of the ignition switch.
  3. Connect a test light between terminal D and terminal C at the steering column connector C207 (harness side).
  4. Use a scan tool to cycle the steering column lock/unlock motor.

Did the test light turn ON in both the lock and the unlock positions?

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Go to Step 14

Go to Step 12

9

Check for an open or short to ground in CKT 1601.

Was a problem found and repaired?

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Go to Step 17

Go to Step 14

10

Locate and repair open in CKT 150?

Is the repair complete?

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Go to Step 17

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11

Check for an open in CKT 159.

Was a problem found and repaired?

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Go to Step 17

Go to Step 15

12

  1. Turn OFF the ignition switch.
  2. Disconnect the BCM connectors C2 and C3.
  3. At the harness side of the BCM connectors C2 and C3, check for continuity between terminals B8 and C6.

Is there continuity?

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Go to Step 13

Go to Step 11

13

Check for an open or short to ground in CKT 1603 or CKT 1604.

Was a problem found and repaired?

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Go to Step 17

Go to Step 16

14

Replace the steering column lock/unlock motor.

Is the replacement complete?

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Go to Step 17

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15

Replace the ignition lock cylinder.

Is the replacement complete?

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Go to Step 17

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16

  1. Replace the BCM. Refer to Body Control Module Replacement .
  2. Program the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Is the replacement complete?

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Go to Step 17

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17

  1. Turn the ignition switch to the OFF position.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Disconnect the BCM fuse #25 for 15 seconds to clear the BCM steering column fail enable mode.
  4. Turn the ignition switch to the ON position.
  5. Clear any BCM DTCs. Refer to Clearing DTCs in Body Control Systems.

Are all the DTCs cleared?

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Go to Diagnostic System Check - Body Control System

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