The engine control unit (ECU) is one of the most important components of a modern vehicle. When it starts to fail, the symptoms can be subtle or can lead to the car not working at all.
Below are the most common signs of a faulty ECU.
Clear symptoms of a faulty ECU
Hard starting or no start at all
Multiple, random fault codes in diagnostics
OBD communication problems
Unstable idle or power limitation (limp mode)
Engine fan running permanently
Excessive fuel consumption or smoke
Problems appearing after flooding, a short circuit or reverse polarity
Why does an ECU fail?
water ingress
short circuits in the wiring
sensitive design (some models)
incorrect work with tuning tools
vibration or impacts in the area of the control unit
