Mass Air Flow (MAF) Sensor
How does a P0100 code trigger the check engine light? This code will trigger the check engine light under the following conditions:
1. The computer receives an excessively high voltage from the MAF Sensor with the engine not running.
2. The computer receives an excessively low voltage from the MAF Sensor with the engine running.
3. The computer receives a high voltage reading from the MAF Sensor under light-load driving conditions.
MAF Sensor circuit open or shorted
Intake air leaks (unmetered air after MAF Sensor)
Defective MAF Sensor
Electronic Control Module (ECM)/Powertrian Control Module (PCM) concern
Monitor MAF Sensor voltage reading while increasing engine RPM. The MAF Sensor value should increase in proportion to engine speed. If not, first check for air leaks at intake tube, manifold and all vacuum lines. Then test the MAF Sensor circuits for opens and shorts. See our article Automotive Circuit Testing 101, if you need more assistance with this. If concern is determined to be intermittent, wiggle test connectors and wiring to attempt to duplicate concern. You may also use the “Get Help” link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific instruction.