V8 Quattro V8-3562cc 3.6L DOHC (PT) (1990)
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Air Flow Meter/Sensor: Description and Operation
V-8 MOTRONIC Air Mass Sensor
DESCRIPTION
The air mass sensor consists of a platinum wire filament (Hot Wire)which is heated by an electrical current. The wire is held in a fixture that
protrudes into the intake air stream where air enters the manifold from the air filter.
OPERATION
The air mass sensor measures the flow of air into the engine without the use of moving parts. As intake air passes over the Hot Wire, the wire is
cooled and more current is required to maintain the wire at the reference temperature. The ECM measures the current flow through the wire and
uses this information to calculate the mass of air entering the engine.
SELF CLEANING
Dirt, dust or other contamination can adversely affect the operation of the air mass sensor. For this reason, the ECM will heat the platinum wire to
approx. 1800°F (1000°C) for 1 second, each time the ignition is switched off, to burn off any contamination. This burn off will occur only if the
engine coolant temperature is above approx. 140°F (60°C), and engine speed has exceeded 2,000 rpm for at least 3 seconds.
SELF DIAGNOSIS
The Mass Air Flow Sensor Signal is monitored by the ECM and sets a fault code if the signal is outside of proper range.
Blink Code # 2232
