Yamaha FI Code 11: Cylinder Identification Sensor — Fix
On Yamaha motorcycles and scooters, FI fault code 11 means no normal signal is being received from the cylinder-identification sensor — the sensor the ECU uses to know which cylinder is on its firing stroke.
- Applies to
- Yamaha motorcycles
- Est. repair cost
- $25 – $170
- Time to fix
- 30–90 minutes
What it means
Check for a loose/corroded connector, damaged wiring, debris on the sensor tip, 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 11; engine won’t start or is hard to start
- Stalling while riding
- Warning light on
How to fix it
- 1
Inspect the sensor connector and tip
1. Locate the cylinder-identification sensor on the engine. 2. Reseat the connector and clean any debris from the sensor face.
- 2
Test and replace
1. Measure the sensor resistance against spec. 2. Replace if out of range, then clear the code.
Frequently asked questions
Why won’t my Yamaha start with code 11?
Without a cylinder-ID signal the ECU can’t sequence injection and spark correctly, so it struggles to start. Check the connector and wiring first.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.