Fail-Safe Operation

If any of the above codes are recorded, the ECM enters fail-safe mode.

Back-Up Function:
If there is trouble with the program in the ECM and the ignition signals (IGT) are not output from microcomputer, the ECM controls fuel injection and ignition timing at predetermined levels as a back-up function to make it possible to continue to operate the vehicle.
Furthermore, the injection duration is calculated from the starting signal (STA) and the throttle position signal (IDL) Also, the ignition timing is fixed at the initial ignition timing, 5 BTDC, without relation to the engine speed.

HINT: If the engine is controlled by the back-up function, the malfunction indicator lamp lights up to warn the driver of the malfunction but the diagnostic trouble code is not output.