Honda PGM-FI Code 18: Camshaft Position Sensor — Fix
On Honda motorcycles and scooters, PGM-FI code 18 means a fault in the camshaft position (CMP) sensor circuit — the sensor that identifies the cylinder cycle for injection and ignition timing. The engine typically won’t start.
- Applies to
- Honda motorcycles
- Est. repair cost
- $25 – $180
- Time to fix
- 30–90 minutes
What it means
Look for a loose/corroded connector, damaged wiring, metal debris on the sensor tip, or a failed CMP sensor. Applies to Honda models fitted with a camshaft position sensor (typically multi-cylinder CB/CBR models). This is a generic Honda PGM-FI code, shown by blinking the FI/MIL warning light (a long blink counts as ten, a short blink as one). It applies to Honda FI models — scooters and underbones like the Click, Vario, BeAT, PCX, ADV, and Wave, as well as CB/CBR motorcycles. Clearing the code needs Honda’s service-check reset procedure (jumping the DLC service connector, or a scan tool) after the fault is fixed.
Symptoms
- FI light on; engine won’t start or is hard to start
- Code 18 (blink)
- Stalling
How to fix it
- 1
Check the sensor connector and tip
1. Locate the camshaft position sensor on the cylinder head. 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 Honda start with code 18?
Without a cam signal the ECM can’t sync injection and spark, so the engine won’t fire. Check the connector and wiring at the cam sensor first.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.