November 2025 – ECUFILES Release
ECUFILES adds two new Cylinder on Demand OFF solutions: Bosch MED17.1.21 (1.4 TSI platforms) and MED17.1.1 (Audi 4.0 TFSI V8).
Cylinder on Demand (also called COD, MDS (Multi-Displacement System), Halbmotorbetrieb, ACT (Active Cylinder Technology) or VCM (Variable Cylinder Management)) is a fuel-saving feature. At light load and steady cruising, the ECU shuts down half the cylinders (e.g., 2 out of 4 or 4 out of 8). The engine runs on fewer cylinders to use less fuel.
While it saves fuel, many drivers dislike it because:
- Power delivery feels uneven
- Throttle response becomes delayed and non-linear
- Noticeable vibration when half the engine is inactive
- Oil consumption can increase due to uneven cylinder temperatures
- The car feels less enjoyable to drive
Our solution completely disables Cylinder on Demand. All cylinders stay active at all times.
The benefits are immediate:
- Smoother power delivery
- Linear and predictable throttle response
- No half-engine vibration
- Better oil consumption behaviour
- A noticeably more enjoyable driving experience
Works on:
- All VW/Audi/SEAT/Skoda 1.4 TSI with MED17.1.21
- Audi 4.0 TFSI V8 models (S6, S7, S8, RS6, RS7) with MED17.1.1
No side effects, no error codes, fully reversible.
Already available in your ECUFILES account.
