What are the symptoms of a faulty ECU in an EFI motorcycle?
2 Answers
When the ECU of an EFI motorcycle is damaged, the vehicle may exhibit the following symptoms: Failure to start: A damaged ECU can directly prevent the motorcycle from starting. Fuel pump operates but does not inject fuel: When the motorcycle's ECU is damaged, the fuel pump may work normally without injecting fuel in the non-ignition state, and the fuel pump relay appears to be in a normal engaged state. No fuel injection during ignition: Even if the owner starts the motorcycle when the ECU is damaged, the vehicle is in an ignition state but still cannot inject fuel. This situation is due to an internal program fault in the ECU, which will prevent the motorcycle from running normally.
That time when the ECU of my fuel-injected motorcycle broke down really gave me a headache—at first, the start button didn’t respond at all, the battery had power but it just wouldn’t ignite. After several hard pushes, it barely started, and while riding, the power was sluggish, acceleration felt like a snail climbing a hill, especially on the highway where the bike jerked intermittently, shaking so much my hands went numb. At idle, the RPM fluctuated wildly, sometimes jumping to 3000 RPM and then dropping to 1000 RPM, the body swaying like a cradle, and fuel consumption skyrocketed—normally a full tank lasted a week, but now it was almost empty in two days. The malfunction indicator light stayed on, and I thought it was a minor issue, but a simple check of fuses and plugs didn’t help. When I pushed it to the repair shop, the mechanic diagnosed it as an internal short circuit in the ECU. That thing is the bike’s computer, controlling fuel injection and ignition—once it fails, the whole system goes haywire. I learned my lesson: don’t let the ECU get wet when washing the bike, and regular maintenance can extend its lifespan by a few years.
