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 C0550 00: Electronic Control Unit (ECU) Performance

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Electronic Control Unit (ECU) Performance | -- | -- | -- | C0550 00

### Circuit/System Description

The electronic brake control module (EBCM) detects an internal malfunction.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

An internal EBCM malfunction exists.

### Action Taken When the DTC Sets

• | The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS)/Electronic Stability Control (ESP) for the duration of the ignition cycle.

• | The multi function display (MFD) displays the ABS Fault message.

• | The multi function display (MFD) displays the Traction Ctrl Off message.

• | The multi function display (MFD) displays the Stability Ctrl Off message.

### Conditions for Clearing the DTC

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

• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

• | The DTC can be cleared using a scan tool.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References

### Circuit/System Testing

DTC C0550 will set as result of internal EBCM circuit fault.

⇒ | If the DTC is set to current, replace the EBCM.

### Repair Instructions

• | Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control Module References for EBCM replacement, setup, and programming