However the smarts of the ICU are also its downfall. The ICU works within a range to be able to raise and lower idle rpms. Instead of adjusting the butterflies of the throttle bodies, the ICU bypasses the TBs by allowing a controlled amount of air to reach the intakes. The further the ICU opens the more air bypasses the buterflies and the higher the idle rpm - and vice versa.

When the idle rpm is a touch too high or too low, the ICU will open or close more and therfore correct the idle rpm. This happens within seconds while running the engine at or around idle.

The problem is that if you intentionally ride the bike very slow e.g. in 2nd gear at around 1000 rpm (like in stop and go traffic), the ICU might interpret this as the idle being too high and correcting it by closing the air bypass. As long as you ride at that speed the rider wont realize the chang in behaviour and will feed in more and more throttle to keep the slow speed.

Once the clutch gets pulled in or the throttle gets closed all the way, the engine will drop in rpms below the point in can sustain a stable idle. The ICU is not fast enough to correct the situation and the engine will die. Very dangerous, especially in heavy traffic.