Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: Tests for an intermittent condition.
- 3: Determines whether the failure is the result of a faulty front axle circuit or the instrument cluster.
- 4: Tests for proper signal voltage to the PCM.
- 5: Tests for proper ignition 1 voltage to the instrument cluster.
4WD Indicator Inoperative
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Transfer Case Control Schematics | ||||
| 1 | Did you perform A Diagnostic System Check - Transfer Case? | - | Go to Step 2 | Go to Diagnostic System Check - Transfer Case |
| 2 | Verify the fault is present. Does the system operate normally? | - | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
| 3 |
|
- | Go to Step 4 | Go to Step 5 |
| 4 |
|
9-14 V | Go to Step 8 | Go to Step 9 |
| 5 | Test the ignition 1 voltage circuit for a proper voltage at the instrument cluster. Does the voltage measure within the specified value? |
9-14 V | Go to Step 6 | Go to Step 7 |
| 6 | Replace the instrument panel cluster. Refer to Instrument Panel Cluster (IPC) Replacement
in Instrument Panel, Gauges, and Console. Did you complete the replacement? |
- | Go to Step 10 | - |
| 7 | Repair an open or high resistance in the ignition 1 voltage circuit. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 10 | - |
| 8 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement
in Engine Controls - 4.3 L, Powertrain Control Module (PCM) Replacement
in Engine Controls - 4.8 L, 5.3 L, and 6.0 L, or Powertrain Control Module (PCM) Replacement
in Engine Controls - 8.1 L. Did you complete the replacement? |
- | Go to Step 10 | - |
| 9 | Inspect the axle switch signal circuit for an open or short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. If OK, replace the front axle actuator. Refer to Electric Motor Actuator Replacement
in Front Drive Axle. Did you complete the replacement? |
- | Go to Step 10 | - |
| 10 | Operate the vehicle in order to determine if the symptom has been corrected. Is the symptom still present? |
- | System OK | Go to Step 2 |