Cold start control

(Continued)

The communication is performed along a two-way dedicated diagnostic serial line connecting the two ECU's.

COLD START CONTROL

During cold starts, the following conditions occur:

• natural poverty of mix due to poor turbulence of fuel particles at low temperatures
• reduced fuel evaporation
• fuel condensation on the inner walls of the intake manifold
• higher viscosity of the lubricant oil.

The ECU acknowledges this condition and corrects the injection timing according to the following:

• coolant temperature
• inlet air temperature
• battery voltage
• engine rating.

Spark advance is exclusively based on:

• engine rating
• coolant temperature.

While the engine is approaching correct running temperature, the ECU pilots the idling actuator to control the amount of air required to ensure engine operation.

Revolution rating is proportionally decreased as the engine temperature increases until the rated engine running temperature is reached.

COMBUSTION CONTROL - LAMBDA SENSOR

When the engine conditions are:

• idling ratio
• medium load.

The ECU process the lambda sensor signal, by means of a specific integrator, and defines the injector opening time.

(Cont.)