For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the 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

### 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 antilock brake system (ABS) dynamic rear proportion (DRP) and traction control system (TCS) are disabled.

• | The ABS/ESC/ETS indicators turn ON.

• | The red BRAKE Warning indicator turns ON.

• | The TCS indicator turns ON.

### Conditions for Clearing the DTC

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

### Circuit/System Verification

Verify that the DTC will clear with a scan tool and does not reset.

⇒ | If the DTC will not clear with a scan tool, replace the EBCM.

### Repair Instructions

Control Module References for EBCM replacement, setup, and programming

### Repair Verification

Diagnostic Repair Verification