Answer
Oct 04, 2025 - 09:10 PM
That 5658 code on a BMW E90 usually points to a valvetronic or eccentric shaft sensor issue — that’s part of the system that controls variable valve lift.
When that sensor goes bad or the motor sticks, the ECU can’t control valve lift properly, and the car either won’t start or it’ll crank but run rough. Here’s what you can check:
- Battery voltage – low voltage will make that sensor freak out. Make sure you’ve got at least 12.4 V before chasing other stuff.
- Valvetronic motor – pull the motor and see if it’s gummed up or stuck. Sometimes cleaning or resetting it helps.
- Eccentric shaft sensor – if it’s oily (they love to leak), it’s probably bad. It sits under the valve cover and leaks oil into the plug, killing the signal.
- Wiring/connector – check the plug going to that sensor. If there’s oil in there, clean it up and inspect for corrosion.
If you clear the code and it comes right back, you’re most likely looking at replacing the eccentric shaft sensor and its gasket. That’s a common fix on these.
The service manual has the full test procedure — how to check the sensor resistance, the valvetronic motor operation, and the relearn procedure after replacement. Perhaps you could let us know more details about your E90, and we'll be happy to help you find the best manual for your case.
