TPS — Throttle Position Sensor¶
Reads how far the throttle is open — the driver's demand — from 0 (closed) to 1 (wide open).
What it is¶
The TPS reports throttle position as a fraction from 0 (fully closed) to 1 (wide open). Where MAP measures the result of load in the manifold, TPS measures the request — what the driver is asking for. The two together tell the ECU both intent and effect.
In Engone, TPS is driver demand. The idle controller moves the actual throttle blade by itself, so the blade can be open while your demand is zero.
Why it matters¶
Several control decisions key off throttle position and especially its rate of change:
- Acceleration enrichment — a fast throttle opening signals a transient that needs extra fuel.
- Idle control — a near-closed throttle tells the ECU the driver wants idle, so it should take over and hold the target RPM.
- DFCO — a fully closed throttle at high RPM is the cue to cut fuel for engine braking.
How to tune it¶
TPS is an input, not a setting. The thresholds the ECU uses:
| Throttle demand | What happens |
|---|---|
| Under about 5 % | The idle controller owns the throttle (blending out over the next 10 %) |
| Exactly 0 %, with RPM above idle + 400 | DFCO |
| 80 % or more | Closed loop switches off |
| Above 75 % while cranking | The clear-flood command (see Cranking Enrichment) |
Rule of thumb
Think of TPS as intent and MAP as outcome. A flat spot on tip-in is a TPS-rate / AE story; a steady-state mixture error is a MAP-cell story.
In the game¶
Throttle is controlled with W and S, at the speed set by
OPTIONS → THROTTLE CHANGE RATE. The vertical slider in the throttle box shows TPS: x%, and the
position feeds the readouts and the control logic in real time.