For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC C0558 4B: Calibration Mismatch

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Calibration Mismatch | -- | -- | -- | C0558 4B

### Circuit/System Description

The coupling control module (CCM) receives messages from other modules over GMLAN which are needed to perform all wheel drive functions

### Conditions for Running the DTC

• | The ignition switch is in the ON position.

• | Ignition voltage is greater than 9 volts.

### Conditions for Setting the DTC

The CCM receives an invalid message from ECM, EBCM, modules over GMLAN which causes the CCM to deactivate.

### Action Taken When the DTC Sets

One or more of the following actions may occur:

• | All Wheel Drive Off (AWD Disabled).

• | Service All Wheel Drive (Service AWD).

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present.

• | The DTC is not detected in 100 consecutive drive cycles.

### Reference Information

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Verification

1. Perform Diagnostic System Check - Vehicle.

⇒ | Diagnose any other Vehicle DTCs before attempting diagnosis of C0558.

2. With Tech 2, view "Signals" Data Display list under EBCM or ECM.
3. Refer to appropriate module for diagnosing any "invalid" signals.
4. If no invalid signals are present, view "Signal Fault" data in "Enhanced DTC Data"
5. Refer to appropriate module for diagnosing that intermittent faulted signal

### Repair Verification

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.