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 0.14-4.8 volts under all normal engine running conditions. DTC P0102 sets when the MAF sensor signal voltage at the ECM is below the calibrated voltage value.
DTC Parameters
DTC P0102 will set if MAF sensor signal voltage is less than 0.14 volts (less than 0.0 g/s) when:
| • | The engine run time is longer than 0.3 seconds. |
| • | The battery voltage is greater than 11.0 volts. |
| • | No TP sensor DTCs have been set. |
DTC P0102 diagnostic runs continuously once the above conditions have been met.
P0102 is a type B DTC.
Diagnostic Aids
To locate an intermittent problem, use the scan tool to monitor the MAF SENSOR with the ignition On, and the engine Off. Wiggling the wires while watching for a change in the MAF SENSOR voltage may locate the area where an open or short to ground in the wiring could lie.
If the ECM loses the MAF sensor signal, it will calculate airflow based on the MAP, the engine speed and the TP angle.
Circuit 416 (CMP/EGR/MAF/MAP 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/EGR/MAF/MAP/TP1/TP2 sensors share the same sensor return circuit 652.
