When the ECU is turned on (or is recovering from a powered reset), the bootloader will enter application mode if the FEPS pin is not asserted and if there is a valid application image in memory.

When application mode is entered, the library initialises the ECU hardware and starts running the application model.

The platform performs various operations in the background including checks on RAM hardware. If a RAM error is detected, an unrecoverable error is raised (resulting in ECU reset) because program execution is otherwise likely to fail in an unpredictable manner.

Similarly non-volatile data is revalidated in the background and treated as if it is no longer available if validation fails. Thus if run-time memory corruption occurs affecting non-volatile data, any subsequent attempt to read that data will be handled in the same way as if the data were not present (default used instead).

Background checking for code or calibration corruption works through the Calibration Verification Number computation on supported targets with the OBD library option. Ensure that the CVN is recomputed continually if run-time corruption checking is required. If it is detected, an unrecoverable error is raised (resulting in ECU reset). This is in addition to boot-time checksum validation.