Diagnostic help

At some time, the engine fuel requirement has been 25% greater than calculated by the control module using information from the mass air flow sensor.

Fault diagnosis first determines whether the pressure sensors show about the same value with the ignition ON, as the mass air flow sensor is later compared with the intake air pressure. If the pressure sensors are OK but the mass air flow sensor is incorrect then check for air leaks after the throttle and thereafter, change the mass air flow sensor.

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:

• Diagnostic status for the diagnosis.
• O2S 1, unit V
• Closed loop, unit %.
• Multiplicative Adaptation, unit %
• Additive adaptation, unit mg/c.
• Purge Adaptation, unit %.
• Air mass deviation from calculated, unit %.

For more information, see FAULT HANDLING III, OTHER EMISSION-RELATED COMPONENTS AND FUNCTION ).