P0100: Mass or volume air flow circuit

What the code tells you on its own

• System. Powertrain. Engine, fuel, air, ignition, emissions and transmission. The overwhelming majority of what workshops bring to the AI.
• Functional group. Air intake and MAF/MAP
• Subsystem. Fuel and air metering

What we see when P0100 turns up

Measured across the diagnostics run through Wrenchlane by independent workshops, not taken from a reference table. Sightings span March 2026 to July 2026.

• 9 diagnostics carried this code.
• 8 separate workshops met it, so this is not one shop seeing the same fault repeatedly.
• 56% of the time it arrived with no symptom description at all, meaning the technician had nothing but the code to work from.
• Most often on Ford, which is where we have seen it most rather than a claim about the fleet at large.

What P0100 usually turns up with

The multiplier is how much more often the two appear together than chance would predict, so a high number means the pair is telling you something a single code is not. Codes rarely arrive alone, and reading the set is usually faster than chasing the first one on the list.

• P2279, Intake air system leak. Seen together 3 times, 51x more often than chance.

What this page does not tell you

A code names a symptom the car noticed, not the part that failed. P0100 on one vehicle and the same code on another can have different causes, and the counts above describe what independent workshops brought to us rather than how common the fault is across all cars. Getting from the code to the cause needs the vehicle: its make, model, engine and what it is actually doing.

Run P0100 against the car in front of you. Enter the code and the symptoms and get ranked probable causes for that specific vehicle, with the checks in the order worth doing them. Free account, no card.

Other air intake and maf/map codes

• P0101, Mass or volume air flow circuit range/performance
• P2009, Intake manifold runner control circuit low, bank 1
• P0102, Mass or volume air flow circuit low input
• P0113, Intake air temperature sensor 1 circuit high
• P2004, Intake manifold runner control stuck open, bank 1
• P2015, Intake manifold runner position sensor circuit range/performance, bank 1