940 L4-2.3L SOHC VIN 88 B230F (1992)
The cold start injector is activated when the temperature is below 0°C (32°F) or below and the engine is below 1050 RPM. Above 1050 RPM the
cold start injector is turned off.
WARM-UP PROGRAM:
This program provides a richer air/fuel mixture until the engine coolant has reached a temperature of 40 - 60°C (104 - 140°F) or above.
NORMAL DRIVING PROGRAM:
During normal driving, the ECU uses various input devices (mostly the intake manifold pressure and intake manifold temperature signal) to
regulate injection frequency.
FULL LOAD AND ACCELERATION PROGRAM:
During full load or acceleration, the oxygen sensor (lambda sond) signal gets interrupted and a richer air/fuel mixture is provided to achieve
maximum engine power. This will also keep combustion heat and catalytic converter temperature at an acceptable level.
DECELERATION PROGRAM:
During deceleration, the fuel injectors are turned off (in all gears) if engine speed is above 1,800 RPM. Injection is resumed between 1,400 and
1,600 RPM, depending on engine temperature.
RPM LIMITER PROGRAM:
At excess RPM the fuel injectors are turned off to keep the engine from overrevving.
SELF ADJUSTING FUNCTION:
The ECU is adaptive to your driving style or environment. It will adjust its calculations according to assimilated input. Whenever the vehicle is
started or driven, the ECU will use the value it has learned from the previous driving period.
SELF ADJUSTING IDLE SPEED FUNCTION:
In time, normal use, wear and coatings will affect the operation of the throttle valve causing less air to enter the intake system. The ECU will
adjust the idle speed to these conditions as well as the current engine load (AC operation, headlights....).
SELF ADJUSTING LAMBDA SOND FUNCTION:
The lambda sond (oxygen sensor) operates in a similar fashion. It senses if the air/fuel mixture is rich or lean and the ECU will adjust the fuel
injector duration accordingly.
This self-regulating function keeps the air/fuel mixture at a constant midpoint. Therefore the need to adjust CO content is eliminated and is not
possible.
EMERGENCY FUNCTION:
There is a "limp home" mode provided when the signal from the intake manifold pressure or other sensor ceases for some reason (sensor defect,
wiring....). This pre-programmed mode will set the fuel injection frequency (opening duration) so the vehicle can be slowly driven to the repair
shop.
SELF DIAGNOSIS FUNCTION:
If the self diagnostic circuit ("on board diagnostics") in the ECU detects a fault in the fuel injection system, it will activate the "CHECK ENGINE"
light. By extracting the fault codes from the diagnostic socket, you can determine what component or components need further testing or
replacement. This system can store up to three fault codes.
