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: Electronic Control Unit (ECU) Performance

### Circuit/System Description

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

### Conditions for Running the DTC

The ignition switch is in the ON position.

### Conditions for Setting the DTC

An internal EBCM malfunction exists.

### Action Taken When the DTC Sets

One or more of the following actions may occur:

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

• | The dynamic rear proportioning (DRP) may be disabled.

• | A DIC message and/or a warning indicator may be displayed.

### Conditions for Clearing the MIL/DTC

• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

• | The EBCM automatically clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

### Circuit/System Verification

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

⇒ | If DTC C0550 is set as 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