Control functions

Control functions

The control unit self-diagnostic system checks signals from the sensors and compares them with permitted limit values:

• fault indication upon start-up
  • warning light on for 4 seconds indicates test stage
  • warning light off after 4 seconds indicates no faults in components that could alter values required by emission control regulations
  • warning light on after 4 seconds indicates fault.
• fault indication during operation
  • warning light on indicates fault
  • warning light off indicates no fault in components that could alter values required by emission control regulations.
• recovery
  • the control unit defines recovery type on each occasion according to the faulty component type
  • recovery parameters are controlled by non-faulty components.

Control of cylinder balance when idling

On the basis of signals from sensors, the injection control unit controls the evenness of torque at idle speed by altering injector control times.

Control of judder

On the basis of signals from the sensors, the injection control unit corrects the amount of fuel to be injected with the aim of improving handling by reducing jerkiness during driving.

The correction is achieved by adjusting the fuel pressure regulator and altering injector control times.

Control of electric balance

On the basis of battery voltage, the injection control unit alters idle speed to ensure sufficient current delivery by the alternator under conditions of high power uptake by appliances.

Idle speed is altered by adjusting fuel pressure and altering injector control times.

Control of turbocharger wastegate

At various engine service speeds, the injection control unit processes the signal from the turbo sensor and determines the amount of fuel to be injected by adjusting the fuel pressure governor and injector control times.

The control unit also controls the opening of the wastegate on the turbocharger via the control solenoid in order to optimise performance under all service conditions.

Control of throttle closure upon engine power-off

When the engine is turned off (ignition turned to OFF), the injection control unit control closure of the throttle valve on the air intake port by means of a solenoid.

This action limits annoying engine shake as the engine is turned off