When calculating the main fuel injection, the CDI ECU determines two parameters:
- moment of injection start;
- injection duration.
The main injection is stopped in the following cases.
- The engine speed exceeds 4700-4800 rpm.
- The amount of fuel calculated for injection is too low.
- Insufficient amount of fuel in the TKVD.
- External (for CDI control unit) impact, for example. traction control intervention (ESP).
- The vehicle is moving in forced idle mode.
- Engine stopped.
The following information is used to form the main injection stage.
- Engine speed signal on a separate circuit (L5).
- Atmospheric pressure sensor signal (Q28/5) at the outlet of the air filter.
- Coolant temperature sensor signal on a separate line (B11/4)
The following information is used to determine the distribution of the cycle quantity of fuel over the injection stages:
- Charge air temperature sensor signal (B17/9).
- Pressure sensor signal in TKVD (В4/6).
- Boost pressure sensor signal (B5/1).
- Air flow and temperature data from the intake air mass sensor (B2/5) (next - MAF sensor) and from the sensor built into the MAF sensor (B2/5/B1) air temperature (for engines code MF4).
- input signal (to the exhaust gas converter) oxygen sensor (G3/2) (MF4).