I've seen too many people struggling with the so-called error 18 with their Ninebot ES1, ES2 or ES4. It is a consequence of a controller not being able to retrieve proper values from the Hall sensors.
The best way to investigate the issue is to proceed as follow :
- Examine the wires (are they melted, is their a short circuit, etc..)
- Look at the inductors, fuse and resistors just in front of the cables on the ESC. I have embedded a picture below showing standard values (except for 36 kOhm which could be different from one ESC to another)
- Asses if the sensors inside the wheel are working properly
(note that the circled area is a simple fuse and the bottom black SMC is a inductor such as the one on the top just bellow the fuse)
In this tutorial, we are going to focus on the last point of the list.
Step 1 : identify the faulty sensor(s)
In order to identify if there is a faulty Hall effect sensor, you have to extract the ESC and remove it from the tube metal case. Turn on your escooter. Use a multimeter in Volt mode, place a probe on the pin of the red wire and the other probe on the black wire. You should get around 5 Volt.
Then, for each of signal wire (yellow, green, blue wires) you have to place one probe on the red wire pin and the other probe on each color at a time. Here is the tricky part. You have to keep the 2 probes on the pins and at the same time move gently the wheel. You should see the value of your voltmeter display 1,5/1,7V for each sensor at some point. If the value is not moving toward that value or is fixed then there is a problem on the corresponding Hall sensor.
TLDR : If you area lazy you can find soldered PCB with Hall sensors. I didn't try but here is an example on Ali : https://fr.aliexpress.com/item/40001066 ... 3f3979a787 Beware of the configuration of the center sensor. On the original PCB, Ninebot uses a different Hall effect sensor.
So what do you need?
- Soldering iron
- Insulation
- Glue
- desoldering braid
- Hall sensors, I bought SS41F from here : https://www.tme.eu/fr/details/ss41/capt ... honeywell/ or yo can buy these cheap clones https://fr.aliexpress.com/item/32687538 ... 6c379F1YTT
Step 2 : Open the wheel
You can other tutorials explaning how to open a wheel, so I won't talk much about it here. Just check this video : https://www.youtube.com/watch?v=gtR9vCQyFpk. To be honest it's as hard as the guy in this video. The trick : put a small bolt below the axe (on the floor), then place your two feet on each side of the tyre, press the feet and with you hands just pull the stator.
Step 2 : Change the sensor(s)
First you have to remove the plastic/silicon/thermic insulation.
Identify your VCC, GND and Signal legs. The easiest way to do it, is to use the multimeter and see current continuity. Place one probe on the RED wire (VCC) on the ESC and check for each Hall sensor which leg beeps. You can do the same with the black wire (GND) and the 3 colors.
Once it’s done, you have to remove the faulty sensor. You can use a clockmaker screwdriver in order to remove the head of the sensor (it is glued), beware not to fucked the layers of metal pieces. Then unsolder the 3 legs and clean the pin holes with some desoldering braid.
Take a brand new sensor and put back the insulation on each leg.
This part is maybe the one where you have to be cautious. If you purchased the sensors I advised, or a least if you use the same sensors for each position (boundaries and center) you can refer to my scheme.
You have to respect the polarity you have identify at the beginning. Some PCB are different from the one in this tutorial. The important thing, is that the middle sensor has to be reversed. It means that labels are not visible. Also you need to cross the legs. Because it’s reversed, it might not fight in the small notch, so don’t hesitate to rip it a bit.
(yes I know it's not the same colour but you get the idea)
Re-solder everything, do a continuity test on each leg and add some glue in the notch.
Bonus PS : Thanks to @SurgeSPB