Based on Video Edukasi Satu Hati S02E01: BELAJAR TEKNOLOGI PGM-FI - What is PGM-FI? What sensors are in the PGM-FI system and what are their functions? Let's learn one by one.
What is PGM-FI?
PGM-FI stands for Programmed Fuel Injection. It's Honda's electronic fuel injection system that replaced carburetors on manual bikes like CB150R, Supra GTR, Sonic 150R, CBR150R. Instead of mechanical jetting, an ECU (Engine Control Unit) calculates perfect fuel amount using sensor data - more efficient, less emission, better cold start.
Core PGM-FI Sensors and Their Functions
1. MAP Sensor (Manifold Absolute Pressure)
Measures intake manifold pressure / vacuum. ECU uses it to calculate engine load. If fails: MIL blink 1-1, engine runs rich or won't idle.
2. IAT Sensor (Intake Air Temperature)
Located in airbox. Measures incoming air temperature. Cold air = denser = needs more fuel. If fails: MIL 1-2, poor cold start.
3. TP Sensor (Throttle Position)
On throttle body. Tells ECU how far you open throttle. Critical for acceleration enrichment. If fails: MIL 1-2 or 8-1, jerking when opening throttle.
4. EOT / ECT Sensor (Engine Oil / Coolant Temperature)
Measures engine temperature. ECU enriches fuel when cold. If fails: MIL 7-1 or 7-2, hard to start when cold, fan not working.
5. CKP Sensor (Crankshaft Position)
Most important - tells ECU engine RPM and piston position for ignition timing. Located near stator. If fails: Engine won't start at all, MIL 8-2 or 9-1.
6. O2 Sensor (Oxygen Sensor) - On some models
In exhaust. Measures remaining oxygen to correct fuel trim (closed-loop). Keeps emissions low. If fails: Higher fuel consumption.
7. Bank Angle Sensor
Safety sensor - cuts engine if bike falls over >60 degrees. Must reset by turning key OFF-ON.
8. Injector & Fuel Pump
Not sensors but actuators: Injector sprays fuel based on ECU calculation, fuel pump provides 294 kPa pressure.
How PGM-FI Works - Simple Flow
Sensors (MAP+IAT+TP+EOT+CKP) → ECU calculates fuel + ignition timing → Injector sprays + Ignition coil fires → O2 sensor corrects. All monitored, if error → MIL light blinks with code.
Why This Matters for Troubleshooting
When your Honda manual bike shows MIL blinking, you can read code via DLC jumper (like in our Engine Won't Start guide). Example: 1 blink long + 2 short = MAP sensor problem. Check our Honda Service Guides category for full MIL code list.
Routine Maintenance for PGM-FI
- Clean air filter - dirty IAT/MAP readings cause rich mixture
- Check throttle body for carbon - affects TP sensor
- Check connectors for water - very common cause of PGM-FI errors in rainy season
- Don't unplug sensors with key ON - will store MIL code
Labels: Honda Service Guides, Electrical System, Engine & Transmission, Troubleshooting
Watch: S02E01 - BELAJAR TEKNOLOGI PGM-FI and our earlier 16 Essential Service Points