Honda PGM-FI Code 9: IAT Sensor — Causes & Fix
On Honda motorcycles and scooters, PGM-FI code 9 means the ECM has detected a fault in the IAT (intake air temperature) sensor circuit. The ECM uses intake air temperature to fine-tune fueling for air density.
- Applies to
- Honda motorcycles
- Est. repair cost
- $15 – $80
- Time to fix
- 30–90 minutes
What it means
Common causes are a loose/corroded IAT connector, damaged wiring, or a failed IAT sensor. This is a generic Honda PGM-FI (Programmed Fuel Injection) code, so it applies across Honda FI models — scooters and underbones like the Click, Vario, BeAT, PCX, ADV, and Wave, as well as CB/CBR motorcycles. Honda shows it by blinking the FI/MIL warning light: a long blink counts as ten and a short blink counts as one (e.g. one long + two short = code 12). Clearing the code usually needs Honda’s service-check reset procedure (jumping the DLC service connector, or a scan tool) after the fault is fixed; simply resetting without repair will let the light return.
Symptoms
- FI/MIL light on with code 9
- Slightly rich or lean running (often mild)
- Minor drop in fuel economy or throttle crispness
How to fix it
- 1
Inspect the IAT connector
1. Locate the IAT sensor (in the airbox or intake duct). 2. Reseat the connector and check for dirt or corrosion.
- 2
Test the sensor and wiring
1. Measure sensor resistance against the temperature chart. 2. Check the signal and ground wires for continuity. 3. Replace the sensor if out of spec, then clear the code.
Frequently asked questions
Is code 9 serious?
It’s usually one of the milder FI faults — the engine 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.