P0102 on Toyota: How to Diagnose & Fix
Mass or Volume Air Flow Sensor Circuit Low Input
1 Toyota model · 1 documented issue · $40-$350 repair
P0102 on Toyota by model: symptoms, diagnosis and fix
The hot-wire mass air flow (MAF) sensor (PN 22204-22010, used across 2003-2008+ Toyotas) becomes contaminated with dust/oil film and under-reports airflow, so the ECM trims fuel lean and sets P0171 'System Too Lean (Bank 1)' and sometimes P0101/P0102. The result is rough or low idle, hesitation and a check engine light. A vacuum leak downstream of the MAF (PCV/intake) can produce the same lean code.
Common Symptoms
- Check engine light with P0171
- Rough or low idle, near-stalling
- Hesitation on light acceleration
- Slightly reduced fuel economy
How to Fix
Clean the MAF hot-wire element with dedicated MAF cleaner (do not touch the wire) as the first step, which resolves many cases. Also inspect the intake boot, PCV hose and vacuum lines for leaks that cause a false lean reading, and check for a dirty air filter. If cleaning does not restore correct airflow, replace the sensor: OEM Denso MAF PN 22204-22010 (~$120-200); avoid low-quality aftermarket MAFs, which frequently re-set the code.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- CRC 05110 mass-air-flow sensor cleaner, 11 oz
cleaning branch before sensor replacement Fitment/availability: Dedicated non-residue MAF cleaner; not vehicle-specific and only for a confirmed contaminated sensor Fitment/availability: Add to Cart live when reviewed
- Toyota 22204-22010 genuine mass-air-flow sensor
confirmed failed early-generation MAF after leak, fuel and contamination checks Fitment/availability: 2003-2008 Toyota Corolla CE, LE, S and XRS 1.8L; exact 1ZZ-FE-era branch in this issue Fitment/availability: Add to Cart live when revi…
- Toyota 22204-28010 genuine mass-air-flow sensor
confirmed failed later-generation MAF after leak, fuel and contamination checks Fitment/availability: 2009-2019 Toyota Corolla 1.8L/2.4L catalog branch; use here for the issue's 2009-2010 2ZR-FE cars and confirm VIN/engine, replaces 2220…
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Sources for this issue (2)
P0102 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0102 mean on a Toyota?
P0102 stands for "Mass or Volume Air Flow Sensor Circuit Low Input." P0102 is a generic OBD-II code meaning the engine computer detected an abnormally low voltage or signal from the Mass Air Flow (MAF) sensor circuit. The MAF sensor measures how much air is entering the engine so the computer can deliver the correct amount of fuel. A low signal tells the computer it is reading less airflow than is actually present, which can cause poor running, stalling, or reduced power. While not usually an emergency, it can affect drivability and fuel economy and should be addressed. On Toyota it is documented across 1 model: Corolla.
What are the most common causes of P0102?
The most common causes of P0102 are: Dirty or contaminated MAF sensor element, Faulty MAF sensor, Damaged, corroded, or loose MAF connector/wiring, Open or short to ground in the signal or power circuit, Dirty or restricted air filter / intake blockage, Vacuum or intake air leak after the sensor, Poor power or ground supply to the sensor. The specific cause varies by vehicle.
How much does it cost to fix P0102 on a Toyota?
Published repair estimates on Toyota range from $40 to $350 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0102 on a different make?
View P0102 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.