Circuit Description
The internal fault detection is handled inside the control module. No external circuits are involved.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0550 ECU Malfunction
Conditions for Running the DTC
The microprocessor runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
| • | The control module detects an internal write malfunction. |
| • | The control module detects an internal checksum malfunction. |
Action Taken When the DTC Sets
If equipped, the following module specific actions may occur:
| • | The antilock brake system (ABS) telltale turns ON. |
| • | The BRAKE warning telltale turns ON. |
| • | The traction control system (TCS) telltale light emitting diode (LED) turns OFF. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | Using a scan tool, clear the DTC function. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module. |
| • | If this DTC is retrieved as both a current and history DTC, replace the module. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is DTC retrieved as a current DTC? | Go to Step 3 | Go to Diagnostic Aids |
3 | Replace the control module setting the DTC as current. Refer to Control Module References in Computer/Integrating Systems. Did you complete the replacement? | Go to Step 4 | -- |
4 |
Does the DTC reset? | Go to Step 2 | System OK |
