Circuit Description
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 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 the MAF sensor signal voltage is greater than 4.8 volts when:
| • | Engine is running for longer than 0.3 seconds. |
| • | Ignition voltage is greater than 11.0 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 could lie.
If the ECM loses the MAF sensor signal, it will calculate airflow based on engine speed and TP sensors.
Important: A direct short to voltage on circuit 652 may cause internal damage to the ECM ground trace, or open the sensor element in the ECT, IAT, and/or MAP sensors.
If DTCs P0103, P0108, P0113, P0118, P0123, P0223, P0341, P0406 and P1271 are set, there may be an open circuit in the 5 volt reference return circuit 652.
