Giant 2021 Stance E+2 - Sudden off

[Kiwi Giant]

My tale of woe which I hope is now over. Back in late July I was riding up the Colonial Knob summit track when at the 9km point I experienced the dreaded sudden off! The RideControl switched itself off, no lights, so I removed the battery and refitted it numerous times, no improvement, no fault code lights, the RideControl would not switch on again, so a slow ride home. I took the bike into Giant Wellington.

They replaced the RideControl under warranty. It took about 2 weeks for parts to arrive in country and fit. After collecting the bike, I was prepping it for its first ride in the garage on the workstand and with it switched on, another sudden off - again no lights, no fault codes. Battery removed and refitted, no improvement. I replaced the battery with a new 800Wh battery that I had just purchased and not yet tried, initially no improvement, then following further battery removal/refits normal operation resumed. A couple of short 5km rides with the 500Wh and 800Wh carried locally without fault.

Next day - Another attempt to ride from home around my Colonial Knob loop, at the 11km point RideControl yet again switched itself off, same, same. I continually tried to switch it back on whilst slowly riding home. Normal ops resumed on the downhill return at the 13km point so I carried on. For the remainder of the ride (17km) including 2 x 250m climbs on Porirua Tip Track and Old Coach Road Track it all operated OK.

Different batteries made no difference so it didn't look like that, RideControl replaced so it wasn't that, I took off the lower cover and pulled apart all the connectors, dry, clean, and no corrosion so not that.

Another ride on the flat the following day - at the 6km point RideControl yet again switched itself off. This was on pavement, no hills, no load to speak of. Very frustrating! More frustrating though was on the return at 12km point I tried the RideControl again and found is was working OK. Not for long though at 13km it switched itself off and would not switch on again. Bike returned to Giant Wellington.

Another long wait, but the guys there are great and extremely thorough. This time they discovered that the Motor to Battery Cable had a fault, another couple of weeks wait for a replacement part and fit. Specifically the fault appears to be in the back of the battery connector where the wires enter the battery terminal fitting, it appears that it is not uncommon for moisture to penetrate this area and corrosion to form. They had another bike with a similar problem in the shop and it was fizzing in this area. It looked like the back of the connector where the wires entered had been dumped in salt water.

So 3 good track rides now, two big climbs and one flat without issue. I'm keeping my fingers crossed.

 

[Kiwi Giant]

Not the part from my bike, but some pics I've collected for info:

 

[DaveMatthews]

Mine had that issue last year. Ended up with the bike being replaced, but my wheels/seat/bars/etc swapped to ne bike. New battery as well.
All has been good for 18 months/2000kms.

 

[Kiwi Giant]

Yes, I think if it had gone on with me being a "crash test dummy" for Giant's ebike development then we would have been talking replacement. I've done 4000km in the 14 months I've owned it. Mind you Giant have had 6 weeks "minding it for me

 

[Kiwi Giant]

I had hoped that this thread was closed with the replacement of the battery connector back in September but unfortunately it was not to be... In mid October after 250 trouble-free kilometres the "sudden off" reoccurred. The bike went back to Giant and the motor has now been replaced.

I got the bike back early this week and so far I've covered 60km with no issues. Fortunately it was a hard fault so Giant Wellington stripped a new Stance and swapped items one at a time until they got to the motor. I'm hoping that this has finally solved the issue, if nothing else the bike is practically new electrically with only the charging point and loom and the rear wheel speed sensor remaining from original. Again Giant have been fantastic about solving the problem.

 

[DaveMatthews]

Glad to hear you are being taken care of properly. My issue was dealt with in a similarly expedient fashion.
Keep it rollin'!

 

[SlowBloke]

I had hoped that this thread was closed with the replacement of the battery connector back in September but unfortunately it was not to be... In mid October after 250 trouble-free kilometres the "sudden off" reoccurred. The bike went back to Giant and the motor has now been replaced.

I got the bike back early this week and so far I've covered 60km with no issues. Fortunately it was a hard fault so Giant Wellington stripped a new Stance and swapped items one at a time until they got to the motor. I'm hoping that this has finally solved the issue, if nothing else the bike is practically new electrically with only the charging point and loom and the rear wheel speed sensor remaining from original. Again Giant have been fantastic about solving the problem.

G'day KG. How has your bike been since these components were replaced. Any further issues?

 

[Kiwi Giant]

Since the motor was replaced over a year ago the bike & motor have operated faultlessly. I've probably covered another 2000km and I'm now out of warranty and contemplating the next step. The 2023 Stance is to my mind a downgrade over my model for more money so I've decided to put that money aside in case I have further issues. It is currently operating well and I may do a bearing replacement and gear relube next year.

 

[SlowBloke]

Since the motor was replaced over a year ago the bike & motor have operated faultlessly. I've probably covered another 2000km and I'm now out of warranty and contemplating the next step. The 2023 Stance is to my mind a downgrade over my model for more money so I've decided to put that money aside in case I have further issues. It is currently operating well and I may do a bearing replacement and gear relube next year.

Thanks KG. Interesting. To give you some background, I just purchased a Trance X E+ Elite which I picked up a couple of days ago. Second ride today and it looks like an overheat issue. A long singletrack climb of a bit over 11kms with 600mtrs elevation gain and ambient temp in the high 20s. Lots of pinchy bits. I used Tour and Active with my torque and assist percentage level settings lower than the factory settings. (40nm and 100% for Tour and 50nm and 150% for Active.) I got to the top okay and sat down for ten minutes for a break and when I went to start off again the battery lights were flashing intermittently with the top assist level light flashing red. (I think that's the code for overheated motor) I guess heat soak from the sustained climb and then sitting without the opportunity for some downhill to cool off. I rolled down for five minutes and tried turning it on again and it came back to life and was fine for the rest of the ride, albeit with no more significant climbing.
It's a bit concerning considering the ambient temp and the fact that I was using low outputs relative to the motor's potential. Some phone calls to make tomorrow.

 

[Kiwi Giant]

Hi Slowbloke.

Sorry to hear about your tale of woe.... It certainly sounds like an overheat warning, did you feel the motor? Was it physically hot? You are probably going to have to involve the Giant Dealer. There are a number of threads dealing with overheating in hot climates (not usually a problem here in Wellington, NZ), unfortunately from what I have gathered none have offered much of a solution.

Good luck, keep us updated.

 

[SlowBloke]

Hi KG,

Yes, it sounds like a root cause has never been fully understood. The solution from Giant seems to be to keep changing parts until it's okay. It seems that they provide good support but it'd be better if they didn't have to provide it at all. I wouldn't call my ride circumstances extreme in any way apart from perhaps the length of the climb. Certainly the ambient temp and level of assist were definitely not. It's a bit of a worry. I've been in touch with the nearest Giant dealer (250kms away) and they'll run diagnostics on it when I next get down there. (Apparently the bike stores the fault codes.) They told me to keep on riding it and monitor.

Thanks for the error code doc. My bike is a little different in that it just has the top tube double row of indicator lights, the right being battery level and the left being assist level. There's no documentation relating to this display that I can find as far as error codes are concerned but I've asked the dealer to find out from Giant what they are. I didn't feel the motor, but the tech at the dealer and I are pretty sure that the light sequence I was getting indicates overheat. Thinking about it, I reckon if I had rolled over the top of the climb and continued on the descent for five minutes before stopping it would have cooled down and the problem wouldn't have occurred.

Cheers.

 

[Kiwi Giant]

Yes you a probably right, the motor is sealed and surrounded by a plastic case. Much of what you see is not motor but covering case. There is minimal airflow through this area. As you've surmised when you stop the temperature will initially rise as that minimal airflow stops and the motor case acts as a heatsink. The gap between the battery cover lower end and the plastic bash plate engine cover is the only airflow entrance and although a lot off people believe that this should be covered to stop water ingress the down side is that it also provides a drying airflow or in your case a small cooling one.

Water ingress into this area is provided for by the drain hole in the bottom of the plastic outer case. The only way water can enter the motor is through the crank seals. Again the motor is completely sealed.

Anyway back to your overheating, one thought is to make sure that the drain hole in the bottom of the plastic outer case is clear and the motor parts covered by the plastic outer case and side covers are not caked in mud preventing that minimal airflow. Another is to look at the Giant wiring loom mess in this area. At my motor replacement my dealer neatly tucked as much of the loom as they could up the tube behind the battery connector. Again having a clearer passage as possible may assist with airflow.

If the motor case is actually as hot as others who have experienced this issue have reported then I doubt any firmware would help longterm as altering the trigger temperature to a higher value risks the possibility that the high temperatures will cause damage instead of it being prevented by a shutdown. Hopefully your dealer can offer some suggestions?

You are correct about documentation, the only Service Manual I have ever seen is dated 2020. Access to operating and service documents, an open channel for comms and feedback on faults and other consumer issues like access to ebike parts online for it's user base are NOT attributes that you associate with Giant.