What is ECU remapping?

Every modern vehicle has an ECU, or engine control unit. It holds a calibration file that tells the engine how much fuel to inject, how much boost to run, when to ignite and where to stop. The manufacturer writes that file to suit every market it sells into, including different fuel qualities, climates and service standards.

Remapping is the process of reading that file, recalibrating it for your vehicle, and writing it back. Nothing is bolted on and nothing is cut out. It is the manufacturer’s own software, adjusted.

How we get to the software

• OBD – we connect to the diagnostic port under the dashboard. This suits most vehicles.
• Bench – the ECU comes out and we connect to the board directly. Used where the port route is closed off.
• Tuning module – a plug-in unit rather than a software change. We only fit these on applications where they work properly.

What you can expect

The realistic result depends on the engine, its condition and what you want from it. A diesel tuned for towing and economy is a different file to a petrol tuned for throttle response. We will tell you what your specific vehicle is likely to give before you book, rather than quoting a headline percentage.

You may see remapping called chip tuning. That is an older term from the days when the chip was physically replaced.