The pedal stops responding near the top of its travel because the tune wrote a driver-wish request higher than the car can produce — and the limits cut it. If the torque ceiling is around 275 Nm and the request says 300, everything past roughly 85–90% of pedal travel maps to the same clipped output. The fix is not a bigger request. It is a more linear pedal curve.
Where this comes from
At the 5 May 2026 Q&A, Denis asked the question directly: do I need to edit the DW maps if they request maximum power that is much higher than the car can produce — many customers ask to remove the dull throttle pedal (~50:51). Thomas answered on a live file; the quotes below reference that recording.
Why the pedal dies at ~87%
“Let it be the torque of this car is 275… if you just write something like 300, then of course you will cause the trouble that the pedal will stop working at some level — maybe 85, 90 percent, or 87 — and it will stop working, because then the limits will cut it. It is just a strange behaviour: the pedal works some percent, and it is not working over some position.”
— Thomas, Q&A 2026-05-05, ~51:09
The request saturates before the pedal does. The last 13% of travel asks for torque the limiter will never grant, so the driver feels a dead zone exactly where they expect the most response. The same protective ceiling shows up across the Bosch torque structure — the driver-wish monitoring pair on EDC17C46 is its harder-edged cousin.
The fix: linearise, don’t raise
“The best idea in that case is not to increase the pedal, if the values are big enough — or even make it more linear, which is somehow very good for the fuel consumption.”
— Thomas, Q&A 2026-05-05, ~52:01
In the live demo the linearisation went downward — Thomas reduced the over-aggressive part of the curve (“as you see, I reduced the pedal”, ~52:17). Factory driver-wish calibrations often front-load the response for a lively showroom feel; flattening that skew is what makes the pedal honest across its whole travel.
What the customer gets:
“It will be a very nice feeling at the road: if you press a bit, it goes a bit. If you press half, it goes half. If you press three-fourths, it goes three-fourths.”
— Thomas, Q&A 2026-05-05, ~52:47
| Approach | Feel | At the limit |
|---|---|---|
| Raise the request (275 → 300) | Sharper low pedal, dead zone from ~87% | Limits cut the request |
| Linearise the curve | Proportional response across full travel | No saturation, no dead zone |
The fuel-consumption bonus
A linear curve also drops fuel consumption. The reason is vibration: your leg moves slightly with the car even when you don’t intend to move it. On a front-loaded curve those micro-movements translate into disproportionate throttle changes; on a linear characteristic the same wobble produces a smaller change (~52:14–52:47). The customer asks for pedal feel and gets economy as a side effect.
Related on Tuners Guild
- The full mechanism: Throttle closes at WOT after tuning: the MAF overflow trap — the overflow signature, the EGR-delete path into it, and the throttle algorithm’s paired maps and delays.
- The hard version of the same ceiling: EDC17C46 no-start after a driver-wish edit — what the monitoring pair does when a DW edit goes wrong.
- The full method: Chip Tuning Diesel — Practice covers the driver-wish structure and the torque model around it on EDC17 and MD1.
Method credit: the answer is Thomas Pirowski’s, from the 5 May 2026 live Q&A; timestamps reference that recording.
Your turn
Have you linearised a driver-wish curve and had the customer comment on fuel consumption — or found a platform where the factory curve was already linear? Post the ECU, what the factory curve looked like, and what you changed. Before/after pedal maps are exactly the kind of thing this thread is for.