GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Transfer Case System Check performed?

--

Go to Step 2

Go to Transfer Case Diagnostic System Check

2

  1. Install a Scan Tool .
  2. Turn ignition ON, engine OFF.
  3. Using the scan tool, select the instrument cluster, command the SERVICE AWD/4WD lamp on.

Does the lamp go on?

--

Go to Step 3

Go to Step 4

3

Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement

Is the repair complete?

--

Go to Step 5

--

4

Replace the instrument cluster.

Is the action complete?

--

Go to Step 5

--

5

  1. Reconnect all previously disconnected components.
  2. Turn the ignition ON, engine OFF.
  3. Use the scan tool in order to clear all DTCs.

Is the action complete?

--

Go to Transfer Case Diagnostic System Check

--