Mass or Volume Air Flow Sensor A Circuit
What it means
The engine computer has detected a missing or invalid signal from the mass airflow (MAF) sensor, which measures the air entering the engine. It then switches to an estimated backup value, so fuel mixture control becomes less accurate and engine performance may suffer.
Symptoms5
- Check engine light on.
- Rough idle or occasional stalling.
- Hesitation or weak acceleration.
- Higher fuel consumption or black smoke from the exhaust.
- Occasional hard starting.
Possible causes6
- Unplugged, corroded or loose sensor connector.
- Broken or damaged wiring between the sensor and the engine computer.
- Lost sensor power from a blown fuse or faulty relay.
- Poor sensor ground connection.
- Failed MAF sensor.
- Engine computer fault (rare).
How to diagnose5
- Read the codes and freeze frame data, and note any other codes for the same sensor.
- Watch the MAF reading on a scan tool at idle and while raising RPM, and confirm it changes logically.
- Inspect the connector and wiring for corrosion, chafing or loose pins.
- Measure power and ground at the sensor connector with a multimeter and compare with the manufacturer specification.
- Check continuity of the signal wire between the sensor and the computer.
How to fix5
- Clean the connector pins and reconnect it firmly.
- Replace a blown fuse or faulty relay in the sensor power circuit.
- Repair the broken wire or poor ground.
- Replace the MAF sensor if power and wiring are good but its signal is still wrong.
- Clear the codes, then road test and confirm the code does not return.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The cost is low when a connector, wire or fuse is at fault, and rises when the MAF sensor must be replaced; sensor prices vary widely by vehicle and part type.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Can I drive with code P0100?
Yes, for short trips and carefully, since the computer uses a backup value, but the engine may stall or lose power, so repair it soon.
Will cleaning the MAF sensor clear this code?
Usually not. This code points to an electrical fault in the circuit, while a dirty sensor more often sets P0101. Start by checking the connector, wiring and power supply.
This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
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