SAE Standard Definition

P0100

Mass Air Flow (MAF) Circuit Malfunction

The MAF sensor circuit is reporting values outside the expected range.

Moderate
Safe to drive beginner Fix within 14 days
Estimated Cost (USD)$20 - $400
BudgetMajor
Estimated Labor~0.5 hours

The Mass Air Flow sensor measures the amount of air entering the engine. The ECM uses this data to calculate fuel injection timing and quantity. When this code sets, the ECM has detected that the MAF sensor signal is outside the normal operating range, which can cause poor fuel economy, rough idle, and hesitation during acceleration.

Symptoms

Check Engine Light on
Poor fuel economy
Rough idle
Hesitation on acceleration
Engine stalling
Black smoke from exhaust

Common Causes

Dirty or contaminated MAF sensor

HIGH

Oil, dirt or debris on the sensing element reduces accuracy.

Faulty MAF sensor

MEDIUM

Internal circuit failure in the sensor itself.

Air leak between MAF and throttle body

MEDIUM

Unmetered air enters after the sensor, skewing readings.

Damaged wiring or connector

LOW

Corroded pins or chafed wires interrupt the signal.

Step-by-Step Diagnosis

1

Inspect MAF sensor

easy

Remove the MAF sensor and visually check for contamination or damage on the hot wire/film element.

Tools:Screwdriver set
2

Clean MAF sensor

easy

Use dedicated MAF sensor cleaner spray. Do NOT touch the element. Let dry completely before reinstalling.

Tools:MAF cleaner spray
3

Check wiring and connector

medium

Inspect the MAF connector for corrosion or bent pins. Check wiring harness for damage.

Tools:Multimeter
4

Check for vacuum leaks

medium

Inspect all hoses and intake boots between the MAF sensor and throttle body for cracks or loose clamps.

Tools:Smoke machine (optional)

Commonly Seen With

P0100 is frequently found alongside these codes:

Related Codes

Frequently Asked Questions

Disclaimer

The information on this page is provided for general educational and reference purposes only. ErrorCodes is not a substitute for professional automotive diagnosis or repair. Diagnostic trouble codes indicate areas for further investigation and do not definitively identify the failed component. The same code can have different causes depending on your specific vehicle, its history, and conditions. Always consult a qualified, certified mechanic before performing repairs. ErrorCodes assumes no liability for any repairs made based on information found on this site.