LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saab >> 1989 >> 900 SPG >> Repair and Diagnosis (Single Page) >> Engine Performance >> Theory and Operation >> Theory/Operation >> Computerized Engine Controls >> Input Devices >> Air Mass Meter
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Air Mass Meter

The air mass meter continually measures temperature, amount, density, and speed of air entering engine intake system. The meter consists of a platinum wire filament located within intake air stream, and a circuit board with a CO adjustment potentiometer.

The wire filament is kept at 212°F (100°C) above the temperature of air entering engine regardless of composition of air entering engine. The air mass meter sends a temperature related signal to the circuit board for processing. Once processed, airflow signal is sent to injection ECU.

When engine is turned off, dirt build-up is burned off wire element by heating filament to approximately 1920°F (1050°C) for one second, 4 seconds after engine is off. The injection ECU then de-energizes air mass meter relay once burn-off cycle is complete.