Fail-Safe Operation
FAIL-SAFE FUNCTIONIf any of the following codes is recorded, the ECM enters fail-safe mode.
BACK.UP FUNCTION
If there is trouble with the program in the ECM and ignition signals (IGT) are not output from the 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 closed throttle position switch signal (IDL). Also, the ignition timing is fixed at 50 BTDC, without relation to the engine speed.
HINT: If the engine is controlled by the back-up function, the MIL lights up to warn the driver of the malfunction but the diagnostic trouble code is not output.