For 1990-2009 cars

### Circuit Description

The electronic brake control module (EBCM) performs several self-tests, for any internal problems, which may affect proper operation.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0550 Electronic Control Unit (ECU) Performance

### Conditions for Running the DTC

• | The ignition is ON.

• | The vehicle has achieved a speed greater than 10 km/h (7 mph).

### Conditions for Setting the DTC

The EBCM detects an internal malfunction.

### Action Taken When the DTC Sets

The following actions may occur.

• | The EBCM disables the Antilock Brake System (ABS)/dynamic rear proportion (DRP).

• | The ABS indicator turns ON.

• | The brake warning indicator turns ON.

• | The traction fault message is displayed.

• | The brake message is displayed.

### Conditions for Clearing the DTC

Certain failures that may cause this DTC to set cannot be cleared. Other failures that may cause this DTC to set may be cleared, at least temporarily, by using the scan tool Clear DTCs function.

### Diagnostic Aids

Replace the EBCM, if this DTC continues to set intermittently.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Use a scan tool in order to clear the DTCs. Can the DTC be cleared? | Go to Step 3 | Go to Step 4
3 | Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text. Does the DTC reset? | Go to Step 4 | Go to Diagnostic Aids
4 | Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | --
5 |

1. Use the scan tool to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

Go to Step 3

System OK