Diagnostic help

When idling, the need of fuel to the engine has been 5 mg/c less than that which the control module had calculated with the information received from the mass air flow sensor.

Fault diagnosis first determines if the pressure sensors indicate about the same value with the ignition ON, as the mass air flow sensor is then compared with the intake air pressure. If the pressure sensors are OK but the mass air flow sensor value is not correct, then air leaks between the compressor and the throttle are checked for first and then the mass air flow sensor is changed.

If the air quantity is OK, then the fuel supply is checked, i.e. pressure, response, pump flow and finally the injectors.

Functions in the diagnostic tool related to the fault:

• Additive adaptation, unit mg/c.
• Closed loop, unit %.
• Purge Adaptation, unit %.
• Air mass deviation from calculated, unit %.