Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Mass Airflow (MAF) sensor measures airflow rate into engine. MAF sensor has a switched battery feed, a ground, a signal circuit and a signal return circuit. As airflow increases, a greater amount of current is required to maintain the hot wires at a constant temperature. MAF sensor converts the changes in current draw to a frequency signal read by the ECM. ECM calculates airflow (grams per second) based on this signal.
ECM monitors the MAF sensor frequency and can determine if sensor is stuck low, stuck high, not providing the airflow value expected for a given operating condition, or not providing signal variation expected during normal operation. DTC P0100 will set if MAF signal indicates an airflow of less than 1.11 grams per second (gm/s), or exceeds the maximum value for a given engine RPM. See MAF SPECIFICATIONS table. Conditions must be present for at least 0.1 second.
For duplication of DTC, ensure battery voltage is greater than 11 volts, DTCs P1220 and P1120 are not present, and engine speed is greater than 500 RPM.
| Engine RPM | Max. Grams Per Second |
|---|---|
| 1000 | 23 |
| 2000 | 32 |
| 3000 | 39 |
| 4000 | 50 |
| 5000 | 62 |
| 6000 | 70 |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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