Dreded speed sensor issue.

[Stan]

Have had an issue with my E+0 , 2019. The red led warning light indicating a speed sensor issue. There is no assist from the motor once this led comes on. Dropped the bike to Lbs. Was told it would be a simple speed sensor replacement. Few days later i was advised by my Lbs Giant is going to replace the motor. ?
Have ridden with the new motor for about 250klms and the issue has returned again. The giant app indicated issue with the sync drive motor. Have tried removing the battery, cleaning the battery terminals, adjusting the speed sensor to no success. Also the battery lock seems to adjusted correctly as there is no play in it.
Anyway, the bike is going back this week. Just wondering if anyone has faced the same issues.
If Giant replaces another motor, and it fails again, i hope i have the right to a refund as the bike is not fit for purpose.

 

[simonk]

I get the impression a lot of bike shops just start replacing parts until the problem goes away...
Can you take the plastic motor cover off and inspect the speed sensor cable? The cable can get trapped/kinked/severed if it hasn’t been routed round the various protrusions correctly. This can then cause a speed sensor error on the controller (red light plus the third power led IIRC). The speed sensor cable is an easy replacement (about 30 quid here in the UK) - search for “Yamaha speed sensor cable”.

 

[Stan]

Tks for the reply. Could explain why its an intermittent issue. Will still take the bike into Lbs as its still under warranty. I always document each issue via email to my Lbs.
Cheers.

 

[Softsand]

I had the red light on my 2020 Trance. App said it was a speed sensor. LBS computer said it was too. After way too long a new sensor arrived but still no go. Further investigation revealed motor required replacement. That fixed it although the new sensor turned out to be faulty.

You may get lucky with replacement like someone else on the forum and get a 2020 unit. That would be a result. Yes, after a second replacement, refund or a new replacement would be on the cards. I’d be chasing the same thing if it happens again to me.

 

[Stan]

Yeah, first time the issue happened and was advised a new motor is needed, i asked if the new pwx motor be installed. But no dice. Was advised the motor mounts were different. Not sure abt that one.
Anyhow Lbs told me to bring the bike in asap, but dont know how long it will take to get the bike back as my state in Australia may go into lock down and all non essential services closed. I will post the outcome . Im hoping its just a pinched sensor cable.

 

[DrStupid]

Mine finally gave me the red light, but didnt stop assisting. If fact, even after turning it Off it kept assisting. Lol. That's what I call fail safe! It's odd though, that I couldn't turn the One controller back ON, unless I waited for the power OFF time-out, or removed the battery, though the motor would still assist even with all the lights showing no power. Strange way to enunciate error an my book.

Anyway, on inspection I found it was only the magnet that had worked it way around the spoke. I readjusted the magnet and have had no errors for two rides.

 

[Stan]

Got my bike back today. Problem was a pinched speed sensor cable, under warranty. All good to go again.

 

[Flatslide]

My Rocky Altitude has had 3 speed sensor failures. The motor will still assist based on torque readings, but the power is all over the place. The bike is still under warranty so replacement through Evo, the Rocky Mountain LBS, isn't an issue. I originally thought the sensor was an inductive pickup, but it is a reed switch which mounts directly next to the rear axle. I think the switch is prone to breaking over time due to being pounded relentlessly on our rooty, rocky dh trails-bit like the rear rim...lol.

 

[friartuckshop]

Mine finally gave me the red light, but didnt stop assisting. If fact, even after turning it Off it kept assisting. Lol. That's what I call fail safe! It's odd though, that I couldn't turn the One controller back ON, unless I waited for the power OFF time-out, or removed the battery, though the motor would still assist even with all the lights showing no power. Strange way to enunciate error an my book.

Anyway, on inspection I found it was only the magnet that had worked it way around the spoke. I readjusted the magnet and have had no errors for two rides.

thats not the speed sensor fault, your ride controller has water ingress, it may sort its self out when it drys out, but will probably shit itself again if it gets damp.

 

[DrStupid]

thats not the speed sensor fault, your ride controller has water ingress, it may sort its self out when it drys out, but will probably shit itself again if it gets damp.

Very possible, it has been wet for months it seems.

It's odd that after repositioning the magnet I've had no reoccurrence of the flashing red light. Perhaps I've had both the water ingres with a touch of ill alighned magnet.

 

[Jed Willy]

Me Too! I purchased a 2019 Giant Trance E+ SX Pro in March 2020 and I have had these same electrical problems with it since the first month of owning the bike its now been almost 3-4months and it continues to get worse. Does anyone have a diagram or visual example of what wiring to look at? I have yet to open up the Yamaha motor to see if there's any wiring issues or obvious reasons why my Giant Trance E+ SX Pro is haunted: accelerates on its own + continues to only provide power to lowest assist mode and not shut off.. RideControl says contact dealer but they dont know what that means and I have tried to get them to just re-set the bike but I just get the common dealer response that it must be the ride control sensor. At this point from reading other's reviews and comments I think its beyond the sensor issue. Since my dealership keeps saying Giant is overwhelmed with warranties due to covid-19 since March and this issue has been a problem since the first month of purchasing the bike from Go-Ride it might be time to take matters into my own hands.

 

[glovemtb77]

Me Too! I purchased a 2019 Giant Trance E+ SX Pro in March 2020 and I have had these same electrical problems with it since the first month of owning the bike its now been almost 3-4months and it continues to get worse. Does anyone have a diagram or visual example of what wiring to look at? I have yet to open up the Yamaha motor to see if there's any wiring issues or obvious reasons why my Giant Trance E+ SX Pro is haunted: accelerates on its own + continues to only provide power to lowest assist mode and not shut off.. RideControl says contact dealer but they dont know what that means and I have tried to get them to just re-set the bike but I just get the common dealer response that it must be the ride control sensor. At this point from reading other's reviews and comments I think its beyond the sensor issue. Since my dealership keeps saying Giant is overwhelmed with warranties due to covid-19 since March and this issue has been a problem since the first month of purchasing the bike from Go-Ride it might be time to take matters into my own hands.

What ever became of this did they take care of you ?

 

[glovemtb77]

I am having an issue with the display throwing a code that is not recorded and when I go in the ride control app and run diagnostics it shows all clear. The dealer app looks at the history in the firmware and it shows no codes stored. Everything runs normally even as the code is flashing away (which is the really good news.) Just amazed at how primitive all the programing on these ebike systems is considering how long they have been out. Not just Giant's firmware. Bosch, Shim Steps, etc.
For future reference here is an older Service Manual on the Giant version of the Yamas.

 

[gmac2]

Problem solved on mine! I started getting the speed sensor problem on my 2020 Trance E+1 a few minutes after a hard whack on a log on the bottom of the bike-motor cover. Ended up struggling out of there mostly without power (waaa). Tried lots of the great suggestions on cleaning battery terminals, etc... and then cleaned magnet on rotor - still would cut out and flash red and the L3 light (speed sensor). Popped the lower cover on motor and quickly saw the speed sensor cable was perfectly centered over a 'high spot' on the motor housing - and my solid contact directly on this while crossing a log smashed the wire pretty good (see pic). I carefully stripped/soldered/heat shrinked each wire and the the whole bunch (3 wires) and tucked away from the area where a direct hit on the bottom cover would do this to me again. Good to go now. Woot!

 

[RustyIron]

Cool that you found the solution. The solution is always there for those who look long enough.

Reading back to the beginning of the post reminds me that many folks think diagnosing complex systems is easy, because there's a computer to tell you what the problem is. And that's true... to a point. The computer will tell us the problem it sees. And that can be helpful... maybe.

Let's remember that the bike has gone nuts, and that's why we're looking at the computer in the first place. The computer is the brain of the bike. So we're relying on the brain of an insane bike to tell us why the bike is bananas.

It's like a psychiatrist relying on a schizophrenic patient to pinpoint the synapse in his brain that has short-circuited and is causing him to hear voices. You can talk to the patient, listen to the patient, and observe the patient. If you get lucky, you cure them after one visit. Other times, you get it wrong on the first diagnosis.