Fuel Injection

The fuel injection control units, through various input sensors, determine fuel injection and the actuation of other output devices. Ignition spark timing is also controlled by the control unit.

The control units have built-in fail-safe mechanisms. If a fault occurs while driving, the control units will substitute pre-programmed values. Driving performance will be affected, but the vehicle may still be driven.

The control units have a self-diagnostic function which allows the unit to store a number of trouble codes in its memory. A Malfunction Indicator Lamp (MIL) informs the driver of system problems. An LED in the control unit will flash to indicate trouble code(s).