Operation CHARM: Car repair manuals for everyone.

Description



DATA TROUBLE CODE: P0101

SYSTEM: Mass Air Flow Circuit

CIRCUIT DESCRIPTION
The Mass Air Flow Meter uses a platinum hot wire. The hot wire air flow meter consists of a platinum hot wire, thermistor and a control circuit installed in a plastic housing. The hot wire air flow meter works on the principle that the hot wire and thermistor located in the intake air bypass of the housing detect any changes in the intake air temperature.
The hot wire is maintained at the set temperature by controlling the current flow through the hot wire. This current flow is then measured as the output voltage of the Air Flow Meter.
The circuit is constructed so that the platinum hot wire and thermistor provide a bridge circuit, with the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
If the Engine Control Module detects Diagnostic Trouble Code "P0101" it operates the fail safe function, keeping the ignition timing and injection volume constant and making it possible to drive the vehicle.

DIAGNOSTIC TROUBLE CODE DETECTING CONDITION
- Conditions below continue with engine speed 900 rpm or less (2 trip detection logic):
- Closed throttle position switch: ON
- Mass Air Flow Meter output: 2.2 volts or more.

TROUBLE AREA
- Mass Air Flow Meter