Diagnostic Trouble Code (DTC): List

Secondary Failure is as follows: If System A has detected a failure of Part X (Primary Failure), System B obtains that information and then detects a failure of Part X (Secondary Failure).

Therefore, it is important to perform the diagnosis for the DTC detected by System A (Primary Failure). For the DTC detected by System B (Secondary Failure) occurred as a chain reaction, therefore performing this diagnosis is not required.

Detection by a single system means the system has detected a failure by itself. The diagnosis for such a failure (Primary Failure) needs to be performed first.

Detection as a chain reaction or Secondary Failure by a single system means that a DTC may be recorded as a chain reaction (Secondary Failure) or by a single system (Primary Failure) depending on circumstances. If no failure is detected at the same control module by any other systems, the DTC is detected by a single system and the diagnosis for it needs to be prioritized as the Primary Failure.

If another DTC is detected at the same control module by any other system, the DTC detected by this (other) system is a result of a chain reaction (Secondary Failure) and the diagnosis for the DTC detected by the originating system needs to be prioritized as the Primary Failure.