Sensors¶
The ECU's inputs at a glance, and how each one feeds the fuel and spark decisions.
What the ECU reads¶
The ECU can't see the engine directly — it infers everything from a handful of sensors. Each one feeds specific decisions. Sensors in Engone are ideal — they don't fail, drift or need calibrating.
| Sensor | Measures | Feeds | Where to read it |
|---|---|---|---|
| MAP | Manifold pressure (load) | Speed-density, table lookups, AE trigger | Throttle box MAP; bottom bar of the table pages; vacuum gauge |
| TPS | Throttle position / demand | Idle control, AE, DFCO | Throttle slider TPS: x% |
| CLT/ECT | Coolant temperature | Enrichment, cold idle, knock, timing | TEMP box COOLANT |
| IAT | Intake air temperature | Charge density, knock | TEMP box IAT |
| O2 / Lambda | Exhaust mixture | Closed-loop trim | Left readouts λ DEVIATION |
| Fuel Pressure | Rail pressure | Injector flow correction, closed-loop gating | Left readouts FUEL PRESSURE |
| Barometric | Atmospheric pressure | Load ratios | Fixed at 101.3 kPa |
| Battery Voltage | System voltage | Injector dead time, spark energy, fuel-pump efficiency, ECU operation | Left readouts VOLTAGE |
Why it matters¶
Tuning is only as good as the signals it's based on. Understanding what each sensor measures — and which decision depends on it — is how you diagnose a problem: a lean condition might be a fuel-pressure issue, a flat spot might be the MAP signal driving acceleration enrichment, a weak start might be a sagging battery.