When calculating the main injected portion of fuel, the CDI ECU determines two parameters:
- injection start moment;
- 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 small.
- Insufficient amount of fuel in the fuel injection system.
- External (for ECU CDI) impact, eg intervention of the traction control system (ESP).
- The car is moving in forced idle mode.
- The engine has stopped.
The following information is used to form the main injection stage.
- Engine speed signal via separate circuit (L5).
- Signal from the atmospheric pressure sensor (B28/5) at the air filter outlet.
- Coolant temperature sensor signal via a separate line (B11/4)
The following information is used to determine the distribution of the cyclic amount of fuel across the injection stages:
- Signal from the discharge air temperature sensor (B17/9).
- Signal from the fuel injection pump pressure sensor (B4/6).
- Boost pressure sensor signal (B5/1).
- Air flow and temperature data from the incoming air mass sensor (B2/5) (further - MAF sensor) and from the air temperature sensor built into the MAF sensor (B2/5/B1) (for engines with code MF4).
- Input signal (in the converter of the exhaust gas) oxygen sensor (G3/2) (MF4).