GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Yukon - 4WD 🢒 Steering 🢒 Rear Wheel Steering 🢒 One or Multiple Rear Wheel Steering Mode Switch Indicators Inoperative

Circuit Description

The rear wheel steering control module controls the ground circuit of each mode indicator individually. The lamps all share a single common input from the interior lights dimming circuit.

Diagnostic Aids

Inspect all connections at the rear wheel steering control module and the rear wheel steering mode select switch for loose or damaged terminals or damaged wiring. Use of the Rear Wheel Steering Diagnostic System Check will help ensure there are not other conditions or DTCs.

Test Description

The numbers below refer to the step numbers in the diagnostic table.

  1. This step verifies that there are no other lighting concerns

  1. This step will verify the operation of the mode lamps and the Rear Wheel Steering systems ability to change mode of operation.

Step

Action

Yes

No

Schematic Reference: Rear Wheel Steering Schematics

Connector End View Reference: Rear Wheel Steering Connector End Views in Rear Wheel Steering.

1

Did you perform the Rear Wheel Steering Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Rear Wheel Steering

2

Are all other lighting systems operating properly?

Go to Step 3

Go to Diagnostic System Check - Lighting Systems

3

  1. Turn the ignition switch to the ON position.
  2. Operate the rear wheel steering mode select switch while observing the mode indicator lamps.

Do the mode indicator lamps turn on/off as expected?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4
  1. Disconnect the rear wheel steering mode select switch.
  2. Turn the ignition switch to the ON position.
  3. Using the scan tool, actuate the affected indicator control circuit.
  4. Test for a ground signal at the affected indicator control circuit at the rear wheel steering mode select switch connector.

Is a ground signal present?

Go to Step 6

Go to Step 5

5

Test the affected indicator control circuit for an open, high resistance or short to voltage. Refer to Circuit Testing and Circuit Testing in Wiring Systems.

Did you find and correct a condition?

Go to Step 11

Go to Step 8

6

Test the four wheel steering mode indicator LED dimming signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

Go to Step 11

Go to Step 7

7

Inspect for poor connections at the harness connector of the four wheel steering mode select switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the rear wheel steering control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

Replace the rear wheel steering mode select switch. Refer to Rear Wheel Steering Mode Switch Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Important: Perform the Learn Alignment procedure. Refer to Wheel Alignment Measurement

Replace the rear wheel steering control module. Refer to Rear Wheel Steering Control Module Replacement in Rear Wheel Steering.

Did you complete the replacement?

Go to Step 11

--

11
  1. Use the scan tool to clear any DTCs.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3