Arduino Nano freezes on car (High throttle)

Hello everyone,

I have started a project with an Arduino Nano v3 and an OLED 1602 monitor from The concept is to connect to my aftermarket ECU to the Arduino and display values on the monitor. The connection is made using RS232, a MAX232 chip to be specific which then talks to the Arduino. The process is that Arduino queries the ECU fast and then reads the stream from the ECU and sends the data to the monitor.

The whole thing is working just fine except from when I press the car. I know it sounds silly but this is exactly what happens. I may cruise in the city or highway for an hour or more and everything is fine. Whenever I go near or hit the rev limiter and change gears fast, the monitor freezes and the TX led stops blinking so the Arduino is not quering the ECU for data.

I believe it has to be related to electrical noise because I know that it rises as the RPM go higher and the engine sensors send more data, the coils ignite faster and the injectors click on and off faster.

Another reason I believe that is because initially I gutted a chinese USB car charger and used its circuit to power the arduino (12v->5v). I had the same problem but all the time.

So I replaced it with a TRACO power unit and as I said before it works great except from when I press the engine hard.

Please help me, my knowledge on electronics stops here, any help is highly appreciated!

Thank you!

Put a noise filter in the power line. They are often sold for car stereos:

Without seeing your code it's hard to say, but it could also be some sort of buffer/array size issue. If the data is arriving faster than you can process it, you may be overflowing an array and writing data where you shouldn't.


John, is it the case with arduino? I mean can it be affected by such noise? The regulator from 12v to 5v doesn't filter this?

Ian, I thought of this but the fact that the engine revs faster doesn't mean that the rate increases. The rate is stable so if that was the case, wouldn't the problem appear even on low revs? It works perfectly.

John, is it the case with arduino? I mean can it be affected by such noise? The regulator from 12v to 5v doesn’t filter this?

Do you mean that you are using the regulator in the Arduino to regulate from your car battery? You have not seen all the warnings about that?

If you read my first post, I have used a TRACO power unit to regulate the power from the 12v car battery down to 5v. This 5v (Actually is like 4.5V) I connected it to the Vin of the Arduino. Is that wrong?