P0103

Diagnostic Chart:

Schematic:

The mass airflow (MAF) sensor measures the speed and density of air entering the intake manifold. The ECM converts this input to a mass of air per unit time to correctly fuel the engine. The MAF output voltage is a function of the power required to keep the sensing element at a fixed temperature above outside air temperature as the incoming air-cools the sensing elements. The output voltage varies between 0.14 and 4.8 volts under all normal engine running conditions. DTC P0103 sets when the MAF sensor signal voltage at the ECM is above the calibrated voltage value.

DTC PARAMETERS
DTC P0103 will set if MAF sensor signal voltage is greater than 4.88 volts (greater than 263.88 g/s) or if the MAF sensor signal voltage is greater than the calculated value for the given engine speed and load when:
^ Condition exists for longer than 2 seconds
^ Engine run time is longer than 0.6 seconds
^ Engine speed is greater than 300 rpm
^ Main relay voltage is greater than 10.5 volts
^ No TP sensor DTCs have been set

DTC P0103 diagnostic runs continuously once the above conditions have been met.

P0103 is a type B DTC.

DIAGNOSTIC AIDS
To locate an intermittent problem, use Scan tool to monitor MAF SENSOR with ignition On, engine Off. Wiggling wires while watching for a change in MAF SENSOR voltage may locate the area where a short to voltage in the wiring may exist.

If the ECM loses the MAF sensor signal, it will calculate airflow based on engine speed and TP angle.

Circuits 2760 (MAF sensor), circuit 2709 (AC pressure/fuel tank pressure sensor) and circuit 1164 (APP sensor 1) share the same 5 volt reference supply (5 volt Ref-A).

The CMP/ECT/IAT/MAF sensors share the same sensor return circuit 2761.

IMPORTANT: A direct short to voltage on circuit 2761 may cause internal damage to the ECM ground trace, or open the sensor element in the ECT and/or IAT sensor.