Yamaha FI Code 41: Lean Angle Sensor — Fix
On Yamaha motorcycles and scooters, FI fault code 41 means an open or short circuit was detected in the lean-angle sensor — the safety sensor that cuts the engine if the bike leans too far or falls. (This is the sensor-circuit fault; code 30 is the actual overturn event.)
- Applies to
- Yamaha motorcycles
- Est. repair cost
- $20 – $140
- Time to fix
- 30–90 minutes
What it means
Usual causes are a sensor left tripped, a loose/corroded connector, harness damage, or a failed lean-angle 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 41; engine won’t start or cuts out
- May appear after a fall, or from a wiring fault
- Warning light on
How to fix it
- 1
Reset and inspect
1. Stand the bike fully upright and cycle the ignition. 2. Check the lean-angle sensor connector and wiring.
- 2
Replace if faulty
1. Replace a sensor that stays tripped or reads out of spec. 2. Clear the code.
Frequently asked questions
My Yamaha won’t start with code 41 — why?
The lean-angle sensor cuts the engine for safety. Stand the bike upright, cycle the ignition, and check the sensor and its connector if it persists.
Last updated July 15, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.