The Engine Control Module (abbreviated ECU, and also known as the Powertrain Control Module or PCM) is the brains of the engine management system.

It controls the fuel mixture, ignition timing, variable cam timing, and emissions control.

It constantly monitors emissions performance via its OBD (Onboard Diagnostics) programming, and it oversees the operation of the fuel pump, engine cooling fan, and charging system.

It also interacts with the transmission controller (if separate), ABS/traction/stability control system, body control module, climate control module and anti-theft systems.

In short, the engine control module performs a wide variety of functions that are necessary to operate a vehicle.

Vehicle manufactures are in a tough position here, they have to build one cost-effective vehicle for all drivers, taking into account tax banding, insurance, performance, price, and economy, gone are the days when if you wanted more power you bought a vehicle with a larger engine. It’s just not economical for manufactures to design and develop new engines for each model in the range or necessary in this modern age.

A good example of this is the Ford Transit van utilising their 2.0 TDCi Engine, the vehicle is available with 3 x power options, 105 PS, 130 PS and 170 PS, the only difference is the map within the ECU, oh and the price.

And surprisingly, many manufactures do offer ECU remapping services, Volvo for instance allows main dealers to remap their vehicles under the Polestar badge, and Mercedes under Brabus.

Whilst the upgrade in many cases is undetectable, the responsible and correct answer to this question has to be “yes”, your insurance company should be notified of any modifications including tuning.

However, the good news is many insurance companies do not penalise you for upgrades of this nature, particularly if you’re tuning for increased fuel economy.