Automatic Level Control
DTC C0550
Circuit Description
When the ignition switch is turned ON, the electronic suspension control (ESC) module monitors communications between its internal microprocessors and performs self-diagnostic tests. If an internal malfunction is detected, the ESC module will store a DTC C0550 in its memory.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C0550 Electronic Control Unit (ECU) Performance
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description.
Conditions for Running the DTC
The ignition ON.
Conditions for Setting the DTC
^ The ESC module detected an internal malfunction.
^ The malfunction must be detected when the ignition switch is first turned ON.
Action Taken When the DTC Sets
^ Stores a DTC C0550 in the ESC memory
^ Disable all functionality
^ Sends a message to the instrument panel cluster (IPC) to display the SERVICE SUSPENSION SYSTEM message.
Conditions for Clearing the DTC
^ Under all fault conditions, the ignition must be cycled before this DTC can change from current to history.
^ The ESC module no longer detects any internal malfunctions when the ignition is first turned to the ON position.
^ A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ Use the IPC clearing DTC feature.
^ Using a scan tool.
Diagnostic Aids
^ Since DTC C0550 is an internal malfunction to the ESC module, there is no repair procedure and the ESC module must be replaced.
^ The ESC module tests for multiple internal malfunctions and will store a DTC C0550 if one or more internal malfunctions are detected. Therefore, depending on which malfunction was detected, and what internal circuitry was affected, this DTC may cause various symptoms.
Test Description
The number below refers to the step number on the diagnostic table.
2. This DTC requires ESC module replacement.
