Yamaha FI Code 22: Intake Air Temp Sensor — Causes & Fix
On Yamaha motorcycles and scooters, FI fault code 22 means an open or short circuit was detected in the intake air temperature sensor — used to fine-tune fueling for air density.
- Applies to
- Yamaha motorcycles
- Est. repair cost
- $15 – $80
- Time to fix
- 30–90 minutes
What it means
Usual causes are a loose/corroded connector, damaged wiring, or a failed sensor. This is a generic Yamaha fuel-injection (FI) fault code, so it applies across Yamaha FI models — scooters and underbones like the Mio, NMAX, Aerox, and Sniper, plus YZF-R and MT motorcycles. Yamaha shows the code as a number on the diagnostic/odometer display, and the engine-warning light comes on. Once the fault is repaired and the ECU no longer detects it, the code clears; cycling the ignition (or using a Yamaha diagnostic tool) may be needed to confirm.
Symptoms
- FI code 22 with warning light on
- Slightly rich or lean running (often mild)
- Minor economy or throttle changes
How to fix it
- 1
Inspect and test the sensor
1. Locate the intake air temperature sensor (airbox/intake). 2. Reseat the connector; measure resistance against the temperature chart. 3. Replace if out of spec, then clear the code.
Frequently asked questions
Is code 22 serious?
It’s usually one of the milder FI faults — the bike often runs almost normally. Still worth fixing so fueling stays accurate.
Last updated July 15, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.