Diagnostic help
WARNING: This page is about a different car, the 2003 Saab 9-3 and 2002 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
At some time, the engine fuel requirement has been 25% lower than calculated by the control module using information 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:
- Diagnostic status for the diagnosis.
- Closed loop, unit %.
- Multiplicative Adaptation, unit %
- Additive adaptation, unit mg/c.
- Purge Adaptation, unit %.
- Air mass deviation from calculated, unit %.