Sur-Ron Light-Bee electrical troubleshooting

[Sebz]

NOTE: If you bike is new, make sure to read the unboxing article before read this

Besides the wrenches and Hex keys you need to maintain your Sur-ron, one of the most important tool is a multimeter. No need to buy a 200$ Fluke. A basic digital multi meter that can measure voltage and resistance is all you need, you can get decent ones for 20$.


This model we used to have was perfect, but run out of stock, so if unsure just get the same online.

FAQ:

• I can't charge my battery
• I turn the ignition and nothing happens
• My Sur-Ron is cutting out while riding but the lights and dashboard remains ON
• My Sur-Ron is slow
• Display and lights work but the motor does not move
• Motor works (might be slow too) but the lights/horn/display wont work
• My Sur-Ron dies completely and/or the lights/dash flash
• Error 6 hall sensor issue
• USB port needs replacement
• Throttle issue
• How to replace the controller
• Error 10 or 17, high motor temperature fault
• Too much regen, not enough regen, turning off the brake sensors. here's how to program the bike
• Broken connector ?
• Stuck battery power connector?

[Sebz]

I can't charge my battery:

Battery appears to be dead and you cannot charge it?

Awaking the Battery after Auto-Sleep mode:

1. Plug the charger into a power bar with a switch (or an outlet with the switch next to it, it's way easier than unplugging/plugging back) . Do not turn on the power bar yet, insert the charger plug into the battery charge port.
2. Turn on the main power, the moment, the red and green indicators of the charger will alternately blink, turn off the charger and then on again.
3. The red indicator of the charger will blink fast (0.5 second per time). The blink time will last to 20 seconds.
4. After the 20 second blink, the red indicator will be a constant light for 10 seconds. During this 10 seconds, turn off at the power point and then on for one time.
5. After Step 4, the “Forced Charging” function of the charger will be turned on. Then, the charger will work normally
6. You may need to do this procedure up to 20-30times.

This video shows you exactly how to do it:

Even easier with a switched outlet or a switched powerbar

Remarks:

1. In Step 3, during the red indicator’s 20 seconds fast blink, please do not turn off the charger. Otherwise, you need to start the procedure again from step 1.
2. In Step 4, the action to turn off and then turn on the charger needs to be finished during the 10 seconds, when the red indicator is constant light. Otherwise, you need to start the procedure again from Step 1.
3. UNPLUG FROM BOTH BATTERY AND OUTLET FOR 10 SECOND BETWEEN EACH ATTEMPT

If you still can't charge after 30 attempts, skip to the next section below and try step #4 and #6

[Sebz]

I turn the ignition ON and nothing happens, no lights, horn or dashboard.

Trouble turning on:

1.Make sure you turn the key and that it is charged. There is a breaker in front of the battery, breaker needs turned on before operating.


Make sure to also check if the screw terminals are tight, if it's loose the power wire could not be making contact!



2. There is a fuse in a small white box, check that the fuse is intact. If not swap it out. There is an extra fuse in the box. Its a 5amp 250 watt fast acting glass fuse (6mmx30mm) if you need another. Without that fuse the controller is not turned ON and the lights and dashboard are not getting any power.





3. Ignition

The ignition contacts could be corroded it's pretty common if water got in.

Remove the 2 bolts holding the USB/ignition assembly and pull from the top, you should have a simple connector with 2 wires, unplug it and measure the continuity between the 2 pins when the switch it ON, if you don't hear a beep them it's possible the switch is finished. You can bypass the switch with a piece of wire to see if the bike will power up.




4. Measure the voltage with a multimeter: f

4A )measure the voltage with a multimeter: flip the ignition OFF ,then the breaker OFF, unplug the battery fully, wait 30sec, and measure from the charge port, you should be reading anything between 45V up to 67.2V depending on the state of charge. write down the voltage, need to have at least one decimal, if your meter cannot give you one decimal it's time to upgrade it to a new one.


4B) Next would be to plug the battery back, Make sure the breaker and ignition are OFF. Plug the main power cables to the battery, plug the communication port. Measure the voltage from the charge port (see attached) and while measuring flip the breaker ON (Write down the voltage as Voltage B)

4)C While measuring on the charge port , turn the ignition "ON" and measure the voltage again (write it down as voltage C).

As you can see in my case the voltage went up a little .. that is because the BMS was sleeping and we just woke him up (really). If you turn off the breaker and wait 30 sec or so the voltage should go back down a little.

So make sure to let the batt rest 30 sec before you start this, then measure the voltage A, keep measuring while flipping the breaker (Voltage B) and the ignition (Voltage C).

YOU should have a slight bump in voltage between B and C. If you don't then try again but wait 1 minute before measuring. if the voltage still goes lower that at rest then there is likely a BMS problem. If the voltage goes down to 0V at voltage B, then you have a short on the controller. If the voltage drops (under 40V or to zero) on Voltage C then you likely have an accessory shorted out. If the voltage slightly drops between B and C then it's likely either a BMS that cannot support a load or a controller that has a problem.

Ignition OFF --------------- Ignition ON


5. IF you had a weird battery reading, like voltage dropping under 45V when you switched the ignition, Unplug both front and rear lights, if one of them is shorted out the main display and the motor wont run. You can access the headlight connector under the ignition and access the rear light connectors from the back of the rear light.

If you are still having a voltage drop then it's not the lights.. it can be another 12V accessory so you will have to unplug the tilt /crash sensor and the DC converter that powered all the accessories (display, lights, USB and crash sensor) .. But continue with the step 6 and then click the link for step 7 .. the converter & sensor unplugging is covered there.

6.. Battery load testing:

Best is to use a 120VAC incandescent bulb or a halogen bulb as they work great with any voltage, at 60VDC they will be roughly 30-40% of the regular brightness. If you have a large resistors be aware that you will need to apply a small load like a light bulb before apply a large load of the BMs will trip instantly.

Unplug the battery from the bike, let it rest for at least 30 secs, measure the voltage from the battery pack. Then connect the light bulb to the discharge port (there is no polarity on a incandescent light bulb). If you see the voltage drop (like these 2 pictures below) then it's likely the battery BMS that has an issue. In this situation please contact support@lunacycle.com

If not please continue testing

Step#7
click here to be redirected to the next phase of tests (you can skip step 1 and go to step 2 as you just done it)

[Sebz]

My Sur-Ron is not moving or is cutting out while riding but the lights and dashboard remains ON

If the lights/display/horn works and they do not turn off or flicker then continue reading this section


Can be either:
1) Brake cutout sensors
2) Kick stand sensor
3) Throttle stuck
4) A connector is not fully "clicked in"
5) Tilt sensor (crash sensor)
6) A problematic light

Your first step when the lights and dash are on should always be to check the error codes : Find the diagnostic and programming cable adapter (see below) then open the battery cover, turn the breaker OFF and unplug the battery connecter and connect this harness to the bike and then connect the other end to the battery.

Put the bike on a bench or sit on it, don't touch the brakes and have the kickstand UP while you check the codes.

The LED will flash is there is a trouble code stored, wire down the code and check the following error code chart

IF the LED is solid red and not blinking please email us directly, it could be a controller failure.

Now if the issue is intermittent (like a brake sensor) it's possible that it wont give you any error code so in this case it's best to unplug them fully.

NOTE: this adapter only works on Sur-Ron X models, it does not work with the MX version (even if you upgraded the controller as the main harness is different).

Click here for error code chart


Note: If you lost yours, click on the picture to be redirected to the product listing.

1) Check the ebrakes. The brake levers are designed to cut power if pulled. In some circumstances such as a crash this connector could come unplugged and the connector may cause intermittent cutout until plugged back into the lever. If you see a cutout, check the ebrake connector! If it is loose of comes out if you pull on it, add a couple drops of superglue to hold it in place.



Disabling ebrakes for full throttle during braking

The goal of ebrakes is to cut power from the motor as a safety measure, however there are instances where this may want to be disabled such as during an actual race, track use, burnouts, or any situation where you need to already be hitting the throttle before you let go of the brake and require extreme agility. Please see the post below for in-depth instructions on how to service the ebrake connection

To troubleshoot best it unplug both sensors, the connectors are under the ignition and usb plate, see picture below to locate them




2) Kick stand sensor, make sure that the kickstand is up and that the wire is not ripped out of the kickstand (near the pivot). In case of a doubt you can unplug the sensor but you will have to remove the bash guard and access the triangular 3 pin connector and unplug it.





3) THROTTLE:

3A) Electronic throttle (2020+ ) does not return back to zero. Sometimes the throttle grip catches on the end of the handlebar, and doesn't return to zero. The controller cuts power if it is turned on, and the throttle isn't at zero. This is a safety feature to prevent the bike from taking off as soon as it's turned on. To fix this, just loosen the clamp holding the throttle on, slide it out just a bit, and tighten the clamp again.

3B) Electronic throttle wires ripped out of the throttle or harness is crushed.

see this section below

3C) Throttle stuck (only for pre-2020 bikes using the mechanical throttle.)

Maybe the cable it too tight and the throttle is not returning to 0, you can adjust the throttle cable on the hand throttle adjuster, just slide the rubber boot, loosen the lock ring and turn the adjustment screw in.

Video explaining how the throttle works. Note: you dont have to remove the Bach guard you can just take a look through the holes in the bash guard to make sure that the cable sheath is in the bracket.

4) A connector is not fully "clicked in"

There are many connectors on that bike and some are critical, if a wire is pulled out a little or a connector is not fully pressed in then the motor can cut out while riding.

Now you will have to remove the bash guard to access these connector. Make sure that you do not pull on any connectors or wires!

Please take a look at this video

5) Tilt sensor (crash sensor)

The crash sensor is located under the top part of the controller, if you have disabled the brake & kickstand sensors, adjusted the throttle and checked the connector and you still get cutouts (without ever loosing power to the dashboard and lights) then best would be to unplug this sensor and test the bike. So far we havent replaced a single crash sensor so it's very unlikely that it goes bad. If you take a huge jump and land hard, you can trip that sensor (happened to me) so keep that in mind that this sensor is not for extreme jumps!

To access this sensor you will have to pull the controller out, it's a little black box between the battery and then top part of the controller.



Please watch this video on how to change the controller, at the 3:00 min mark Matt is pointing at the crash sensor:

https://www.youtube.com/watch?v=MsRqIB9VMQM&t=5s

6) Rear or front light is pulling the brake cut-out signal.

Disconnect both wires off the rear light and disconnect the front head light (front head light connector is located under the ignition housing). Make sure the 2 rear light wires are not touching anything.

[Sebz]

My Sur-Ron is slow (speed limited under 30mph or stuck in EP mode)

Sur-Ron low power mode is likely engaged, in that mode the throttle may even feel jerky, like hard to control your speed, so just follow this and your bike will behave better!

Please click this link to see the video on how to change from full power to street legal and vice-versa.

On the Light-Bee this is a (very) low power mode (like 8-10mph) on the Light-Bee X (LBX) it's a street legal mode (if that applies to your state/country) and it's locked to 25-35mph (feels like EP mode). Throttle feel is also not the same as the un-restricted mode.

Now here is the trick, If your bikes was bought before May 2019 then:

Cutting this wire will limit both power AND speed depending on the model you have . In theory you could put a switch here when you go offroad but the idea is you simply cut the looped green/black wire.

If your Bike came with the factory street/slow mode, just look for the green/black wire under the black sheath and crimp or solder both ends together (or twist them together if you can't wait!)

If your bike was bought after May 2019 then: It's the opposite, cutting the green/black wire will make you bike fast again!

NOTE: Cutting the full green wire will not make you bike faster and it will disable the communication with the battery and also prevents you from using the diagnostic cable. Please make sure you cut the green wire with a black stripe

[Sebz]

Display and lights works but the motor does not move?

Rear wheel is also a lot harder to turn? could be a sign of a shorted phase so check the error codes and continue with the spin test.

Before continuing with this section make sure you check all the sensors and connections covered here: CLICK ME That includes using the diagnostic adapter below

Put the bike on a bench or sit on it, don't touch the brakes and have the kickstand UP while you check the codes.

The LED will flash is there is a trouble code stored, wire down the code and check the following error code chart


IF the LED is solid red and not blinking please email us directly, it could be a controller failure.

Now if the issue is intermittent (like a brake sensor) it's possible that it wont give you any error code so in this case it's best to unplug them fully.

NOTE: this adapter only works on Sur-Ron X models, it does not work with the MX version (even if you upgraded the controller as the main harness is different)

Error code chart



Error 14 : If your Sur Ron powers on, but the throttle won't work, turn the key off and give it a twist. If it doesn't return with a snap, maybe that's the problem. Sometimes the throttle grip catches on the end of the handlebar, and doesn't return to zero. The controller cuts power if it is turned on, and the throttle isn't at zero. This is a safety feature to prevent the bike from taking off as soon as it's turned on. To fix this, just loosen the clamp holding the throttle on, slide it out just a bit, and tighten the clamp again.

Wheel spin test

If you don't have an error code, the first test should be the wheel spin test, see if the rear wheel spins without much effort. If you can't rotate it with a finger or 2 then it's possible that the controller is shorted out

Take a look at this video:

f you havent inspected the connection yet then it's time to do it, dont pull on the wires, just press them in firmly, check if there aren't any wires pulled out of a connector.

Please watch this video:

If the motor/rear wheel spins fine and all the sensors are unplugged and you checked every connection then it can still be the controller or a bad connection in the harness. Best would be to take a video of the issue and email support@lunacycle.com

[Sebz]

Motor works (might be slow too) but the lights/horn/display wont work

This failure state is uncommon but is something you could look for if having problems.
The red and black power wires going to the controller has a small red wire soldered to the ring terminal as seen below (The black has the same little wire so check the black too). This goes to the 12VDC voltage converter. If this becomes desoldered or breaks off it will prevent the lights, US, horn and dashboard light up but also could make the motor run slow,

You will need to pull out the controller you can use this video to help you out removing the controller. Just make sure you removed the battery before proceeding with this

Once you have the controller pulled out this is what you need to look for:

INSPECT BOTH POSITIVE AND NEGATIVE,

[Sebz]

My Sur-Ron dies completely and/or the lights/dash flash

Before continuing with this section make sure you check all the sensors and connections covered here: CLICK ME

Wiggle the key a bit to see if the issue gets worst of better, it could be a finicky ignition barrel

Unplug the lights. Both rear lights and any aftermarket modded lights (fisher light headlight etc) one at a time, then go to unplug the DC 12V converter under the bashguard . Under a very few limited circumstances we have seen this cause the bike to show as dead.

If your Sur-Ron display/lights flash 1-6 times and shuts down and 30 sec later it starts to flash again in a loop then it's possibly the battery BMS that is acting up. Best thing you can do is to leave the ignition and breaker ON and then connect the charger to the battery, if the charger is charging you can use the current flowing into the cells to actually power the light and dashboard (and enough to make the wheel spin slowly unloaded) So while charging if the lights stays ON then it's very likely that BMS is acting up. So go down this post to step Blogs and do the controller bypass. If the lights and display works then email Luna Cycle at support@lunacycle.com (best would be to make a video of the issue as the support agents will ask for it)

If your Sur-Ron does not do the 5 flash thing and is just dead then please continue with the troubleshoot:

First question, do you have the diagnostic adapter cable (click this link) if yes please turn off the breaker and install it between the bike and battery, flip the breaker and tell me how many times the red LED blinks. IF you dont then please continue. If you do have it and does not blink then please continue.


The first step would be isolate the issue.. it can be the battery or the controller or just a loose connection.

1A) measure the voltage with a multimeter: flip the ignition OFF ,then the breaker OFF, unplug the battery fully, wait 30sec, and measure from the charge port, you should be reading anything between 45V up to 67.2V depending on the state of charge. write down the voltage, need to have at least one decimal, if your meter cannot give you one decimal it's time to upgrade it to a new one.






1B) Next would be to plug the battery back, Make sure the breaker and ignition are OFF. Plug the main power cables to the battery, plug the communication port. Measure the voltage from the charge port (see attached) and while measuring flip the breaker ON (Write down the voltage as Voltage B)

1)C While measuring on the charge port , turn the ignition "ON" and measure the voltage again (write it down as voltage C).

As you can see in my case the voltage went up a little .. that is because the BMS was sleeping and we just woke him up (really). If you turn off the breaker and wait 30 sec or so the voltage should go back down a little.

So make sure to let the batt rest 30 sec before you start this, then measure the voltage A, keep measuring while flipping the breaker (Voltage B) and the ignition (Voltage C).

YOU should have a slight bump in voltage between B and C. If you don't then try again but wait 1 minute before measuring. if the voltage still goes lower that at rest then there is likely a BMS problem. If the voltage goes down to 0V at voltage B, then you have a short on the controller. If the voltage drops (under 40V or to zero) on Voltage C then you likely have an accessory shorted out. If the voltage slightly drops between B and C then it's likely either a BMS that cannot support a load or a controller that has a problem.



1C) While you are at it inspect the breaker screw-on terminal, if they are loose the wire is maybe not making good contact.





1D) Important : Inspect the fuse and the ignition like step 2 here, a bad contact on these can lead to intermittent issues



2) Next step would be to pull the controller out a little and inspect the the little wires soldered to the main power lug on the controller.


Just click here to know how to do it and what to look for

If one is not soldered properly then you will need to solder it back! There is one on the red and one on the black!

Dont reassemble the bike yet until you test the bike! The next few steps will require you to have the bash guard and controller out.


3) If you havent inspected the connection yet then it's time to do it, dont pull on the wires, just press them in firmly, check if there aren't any wires pulled out of a connector.

Please watch this video:

4) Unplug the DC-DC 12V converter (if you haven't done it already) from the system AND unplug the crash sensor (if the crash sensor is plugged the bike will play dead as it needs 12V to give the Go to the controller, so make just not to over look this step.). the Crash sensor is behind the controller as shown in the previous video at the 66 sec mark (step #3).


Try the bike, you wont get any accessories working but it can help to see if there was an sensor pulling a voltage down, see previous at the 30sec mark to know what to unplug.




5) Now it's time to disconnect the controller power from the battery, so make sure the battery is fully unplugged (very important). Then using an Allen wrench remove the bolts securing the red power terminal, once it's off the controller take some electrical tape and wrap the copper lug so it can't short out on the frame or the negative post. Put the battery back in and flip the breaker ON and the ignition, does the lights and dashboard flicker now or are they staying on? IF they are ON that means the controller is likely damaged and needs to be replaced. If lights are still flickering then it's in the harness or in the battery.

SO if the lights and horn work, then remove the controller and test the resistance like this:

So if you don't measure a short on the controller +&- but the lights and horn did work when you unplugged the controller, it's still possible that it's not the controller that is issue if the dash and lights work fine once you unplugged the controller. That test only confirms that the battery can power a small load (light and dashboard). So I would advise you to add a load on top of the headlight and dashboard, so try the horn too. And make sure you measure the voltage of the battery unplugged and then when the light dash and horn are used. if the voltage drops one bit it can be an indication of the BMS fault. If you get no voltage drop what so ever then it could very be the controller.

So if the controller is the suspect, measure the resistance between the positive and the negative of the controller. (the controller power lug nuts, not the battery wires. You can leave the negative plugged, it's ok, just need the positive to be unplugged. Make sure that you have waited a few minutes since you unplug the positive so the capacitors in the controller don't have any energy left in them. Measure the resistance .. if you have 0 ohms it's shorted, if you have a very high number (or OL, over load) it's not shorted. If it's shorted then you need to replace it.

Just make sure that you tighten the main power lugs back properly, you can use a drop of blue locktite on the thread so it wont loosen up overtime. And while your at it , use dielectric grease over the lugs to prevent oxidation/corrosion! On your next big maintenance inspect your connection again.

6) This next step only applies to the V2 battery, from mid 2018 till the end of 2019, so if you are unsure about the version of your battery, email support@Lunacycle.com and ask to be assigned to Seb.
ISo if the controller turns out ok then chances are that the issue lies in the battery BMS or the wiring harness in the battery. Don't loose hope yet there is a known fix that you will likely be able to perform and will be a permanent fix! So far 9/10 times it's this little wire

The procedure is on a PDF that you can download here, if you have any questions or unsure about your results please email LunaCycle at support@lunacycle.com , ask for Seb and make sure to write down what tests you did, your measurement and attach photos and videos!

---

[Sebz]

Hall sensor related issues: Stuttering motor, error 6, motor running in reverse and weird motor behavior.

If you have stuttering, motor running in reverse or weird motor behavior you can start with this link in red below , if you have error 6 or verified that the magnet is aligned, please follow this section below.

Hall sensor magnet adjustment link


If you have Error 6:

As the the error code guide this is a "motor Hoare coil malfunction" We can only suppose that this means "Motor hall sensor malfunction".


So your first step would be to check the hall sensor connector, it's the big black 6 pin connector (see red arrow on the picture below) inspect that all the wires are still there and no wire is pulled out. make sure that both ends are locked in together.



Now hall sensors are 3 tiny "Hall effect" sensors positioned in the motor and basically their purpose is to tell the controller were the rotor (rotor magnetic fields changes the status of these sensor).

So you have 3 phases and each has their hall sensors, Each sensor has 3 pins, one 4.5V supply, one ground (black wire) and the output signal (green yellow and blue). The red and black are common to all 3 sensors. So if you measure the voltage between the black and red (6 pin connector from the motor) you should be getting around 4.3-4.5Vdc. Now to be able to measure the signal of each you will have to be able to rotate the motor very slowly as you will want to see the signal going from 0V to 4.3V each time the magnet crosses each hall sensor.


Best way to do this is to remove the plastic cover of the main output shaft of the motor and put a 17mm socket wrench in it, so that way you will be able to turn the motor one notch at a time. But before you test anything make sure that the connector is good and that all the pins are making contact and no wire is pulled out.

You also need to unplug every sensor before your start this test, it's possible that a bad sensor could be influencing the hall sensor signal, so please make sure all your sensors are unplugged before testing (crash sensor, kickstand, brakes)



Now the next step will require you to flip the bike over and remove the bash guard to access the hall sensor connector. Make sure to turn the ignition OFF and leave the battery in. You don't need to remove the controller and motor like I did on the video... the motor was already out so I left it there so it would be easier to show you.

You will need a multimeter with good "pointy" tip and likely a second set of hands to turn the motor while you probe the voltage.

Now start by turning the ignition to ON and then measure the voltage from the RED and BLACK core, you can poke through the wire insulation if your meter tips are too fat to fit the back of the connector. Just make to to wrap them in electrical tape after. You should measure a constant 4.3-4.5Vdc, I will use 4.5V as a reference.

Next move your red probe to any of the 3 hall sensor signal wire (Bleu, yellow or green), you will either measure a 0V (or very low voltage) or a 4.5V, now it's time to rotate the motor until you get a change in the signal like this video. IF you don't get any voltage shift (like it stays at zero) make sure that your meter tip is touching the wire. If it stays at 4.5V then you likely have found the issue. Repeat with the 2 other colours make sure they all switch from 0 to 4.5V each 4-5 motor notches. If you have any signal that does not move up and down then one sensor is bad. IF you turn the throttle and let the motor run you will see a 2.5V average voltage coming from it (your meter is not fast enough to pickup the alternating voltage (0-4.5-0V...)

Now if you get a good signal coming off all 3 hall sensors and you still have the error 6 or getting that jerking issue then it's likely the controller that is damaged or that the magnetic disk on the motor shaft has moved, if it's the case click below to be redirected to the Hall sensor magnet adjustment link

If your hall sensor board is defective, here is how to replace it:

How to replace the hall sensors

---

How to adjust the hall sensor board

If you are reading this that means you measured the hall signal and got the right voltage changes on all 3 lines. (first and second test on that post). You do not have an error code and the bike just stutters from a start and if you kickstart it you can sometimes get it going.. that could be a hall sensor adjustment that you need.

Then since you got nothing to loose and are about to replace/repair the motor you can try to adjust the hall sensor board. See see next picture below

You need to remove the side cover, then mark with a sharpie the actual position of the sensor so you can put it back where it was. Then loosen the board and move it a little on either direction and see if it makes the motor run smoother. You can dial it with trial an error using your battery as the power source , pin the throttle and use your ear and gut feeling to get the highest rpm and smoothest acceleration. So if at some point you got it to run fine from a stop then you would just need to fine tune it to get it perfect. It is just a matter of keeping the throttle pinned down and moving the board slightly so you get it to spin the fastest.

TIP: remove the chain or the belt it will be easier and way safer for you.

---

Weatherproof or Waterproof?

Click here and scroll down to the bottom of that forum post

[Sebz]

Throttle problems

If you think you have throttle problems first step would be to check the error codes with the LED programing adapter (or called error code adapter) and see if you have any error codes, put the bike on a bench and give it a few throttle twist until you experience the problem you've been having. Could be error 14 , error 15 or no error code.



If in any case the motor when to full throttle without even touching the throttle then open a support ticket asap

Error 14 : If your Sur Ron powers on, but the throttle won't work, turn the key off and give it a twist. If it doesn't return with a snap, maybe that's the problem. Sometimes the throttle grip catches on the end of the handlebar, and doesn't return to zero. The controller cuts power if it is turned on, and the throttle isn't at zero. This is a safety feature to prevent the bike from taking off as soon as it's turned on. To fix this, just loosen the clamp holding the throttle on, slide it out just a bit, and tighten the clamp again.

Error 15 ( and also error 14) could mean there is a problem with the wiring, most of the time it's a wire got pulled out (ripped from the little circuit board inside the throttle body). In very rare cases it could means the wires in the main harness are crushed and touching or in extremely rare cases it means the controller has a problem.

The first step would be to replace the throttle with a new one, or test the signal:

SR throttle test

You have 3 wires going to it. So remove the bash guard to expose the throttle connection, it's a triangle shaped 3 pin connector that is inside the rubber black boot, locate the 3 wires. red black and green (they all have a white stripe on the wires). Leave the throttle connected. put the rear up in the air or remove the chain to be safe



When powered you should have between 4.2V to 5VDC between the red and black

You should have 0.85V between the black and the green (throttle at rest)

And 3.6V at full throttle between the green and black.

You will have to poke thought the insulation of the wires if your probes are too big to fit the back of the connector.

SO if your issue is not intermittent and you have the right voltage range then it's likely not throttle related. Might be be the controller...


Replacing the throttle

There are 2 model , the mechanical throttle and the electronic throttle. Pre 2020 bikes came with the mechnical unit and the 2020 bikes now have the electronics one.

The mechanical throttle is a 3 parts system, the speed controller (AKA throttle box), the cable and handle. We have a complete kit here and installation video :

https://lunacycle.com/sur-ron-cable-...onversion-kit/

The E-throttle is a complete plug and play unit, if you have the mechanical throttle you can convert to the E-throttle

https://lunacycle.com/sur-ron-replac...tric-throttle/



IF by any chance you cannot find the needed replacement part you can always convert your Sur-ron to an aftermarket throttle!

The Sur-ron uses a 3 wire hall sensor based throttle so basically the option are endless, you can pick any throttle we have in stock and convert it to your Sur-Ron

Please watch he video below, I will explain how to use any electronic throttle on your bike

NOTE: before cutting and splicing anything make sure to remove the battery and then let the controller capacitors drain (you just need to flip the breaker and ignition on without a battery attached)

The click version were I only show you the pinout of the throttle connector.

Testing the aftermarket throttle

[Sebz]

Motor temperature sensor

Error 10 or 17 (HIGH motor temperature)

IF you have error 10 or 17 when the motor is cold to warm then it's a likely a sensor issue. There is no way you can overheat this motor with the stock controller riding in normal weather riding the bike in normal conditions. Even at twice the power on a modified one we have no overheating issues.

Now changing the thermocouple (temp sensor) is quite a complicated job and if it was my motor I would just bypass the sensor since it's not necessary. Best is to test it!


You need to locate the hall sensor connector, it's the boxy black connector coming out of the motor. Unplug it locate the white and black wires, and set you multimeter to resistance (OHM's) and mesure on the connector pins the resistance between both wires at room temperature. It should be around 570 ohm. IF you have way more than this the temp sensor is bad.. See the controller will drop the power if the temp sensor's resistance goes over 720-750 ohms. Measure yours and let me know.

If the temp sensor is off, then just have to bypass it using a 560 ohm resistor* (or around that value 560 -620) between the white wire to the ground (you don't have to cut anything) , you can just take a little bit of insulation off the ground (black wire) of the hall sensor and the white wire and solder the resistor across both. Then take a piece of wire to short the temp sensor to the ground. This is what happens when the temp sensor is cool, it's shorted to ground but as the temp rise the resistance rises to a point were the white is almost like it's unplugged, then the controller shuts down. So if the white wire is unplugged the motor wont run!

See this picture, you can see the black and white wires, these are the temp sensor (thermocouple)

*: Some reported that just shorting the black and white wires works too, some reported you need a resistor. This might be due to controller firmware changes from different revision.




How to test the temps sensor:


What resistance you should be measuring at room temp (around 68-72F)


What resistance when the motor is at 50Celcius ( 122F), This motor was left in a oven for a full day

[Sebz]

Broken connector:

If it's a Furukawa connector (like the 6 wire connector plugged into the battery) then please watch this video:

[Sebz]

Stuck or melted main power connector

This happens when the connector gets loose a bit and with the higher resistance then it gets hot and can melt the plastic and in some cases it can also weld itself. So that is why it's part of the basic maintenance of the bike as shown here in the main manual

This video show you how to prevent it but also trick on how to remove it if it's not welded shut. If it's welded and impossible to remove then you would have to contact us as you will have to send the battery top back to us for repair and possibly the power wiring.