4 THINGS YOU NEED TO KNOW…
Information is king
Sensors are the eyes and ears of the ECU. There are sensors everywhere on the latest high-level bikes – airbox pressure, inlet manifold, throttle butterfly position, fly-by-wire throttle, knock sensors, cam position, crankshaft position, gear position, coolant temperature and two lambda sensors in the exhaust – one before and one after the catalytic converter – and that’s just the engine.
You also have sensors around the bike. Both wheels have speed sensors, some have tyre pressure sensors and many bikes now have an IMU (Inertial Measurement Unit). This clever device, made by Bosch, is a multigyro and accelerometer that helps the ECU to understand what the bike is doing, how fast it is accelerating, braking or how far you are leaning over. This is essential for determining levels of traction control and has allowed cornering ABS to become as accurate as it is.
With all these advancements comes more complex dashboards. Your modern dash is an integral part of the ECU and can display exactly what it’s doing. And even the dash can have sensors – to make it brighter or darker, depending on ambient light conditions.
What else does it do?
The ECU makes sure you can’t ride off with your sidestand down, it works as an immobiliser, operates all the warning lights, tells you when you need fuel and even records data.
‘ Friends talk about having an ECU reflash – what is it and should I have the work done on my bike?
Your ECU has set maps that are programmed in the factory. These make sure your bike runs as it should. But, just like any computer, a specialist can get into these programs and change them for the better. Race or trackday bikes often have the fuelling adjusted just as an older bike would have its jets and needles changed in its carburettors, the RPM limit raised, traction control optimised or engine braking characteristics changed. In fact, there is often more adjustment available in a standard ECU than in a racekitted ECU.
Any adjustments are usually made in conjunction with a dyno, to simulate the bike being used. Be aware of anyone offering an ECU reflash service where you post them the unit and they do the work before posting it back. All bikes are different and it’s best to have the work done with a dyno operator.
Getting your ECU reflashed isn’t just for track bikes – it can improve a road bike, too. Noise and emissions tests on new bikes are performed at certain revs, so there are often flat spots in those ranges for the bike to pass. These can be improved if not eliminated, as can fly-by-wire throttle behaviour, as well as often finding more power. But if you do have your bike’s ECU reflashed, you’re likely to invalidate your warranty. And don’t think because you can’t see any difference, your dealer won’t know – all they have to do is plug their computer in and they’ll know straight away.