this is where the software comes handy because you can test throttle voltages. I’m leaning towards the main voltage of the pack, the % is not accurate in these cars. does it has factory lithium or agms?
1 Like
If I install a different controller, either new or used (to replace this one), would the VCM/BMC need reprogramming to recognize this different controller or would it simply be plug-n-play?
I think what he is asking here is if the new controller is installed (for instance → pulled from another car) will the VCM/BMC play with it nicely?
or will the any of the components need some tech programming/input/counseling to accept the strange new device as one of the family?
This GEM has factory Leoch AGM 6Vx8. The problem w this e6 is consistent w full pack w all batteries w <0.5V btwn each.
This is where I stand today…all components/wiring (affecting drive) periphery to the motor controller and VCM have been checked and are operating normal. I want to believe the VCM has a less probability of failure (controlling signals) than the controller which drives electromechanical devices (contactor/motor) and the fact that the controller ‘might’ not be operating normally due to the Fault LED not providing any feedback when it’s obvious it should when the Encoder and Motor Temp Sensor are disconnected individually. So w no DVT or Wrench to isolate deeper, I’m settling on replacing the motor controller…the owner is in need to bring this GEM back online asap.
recommendations who to call to order and program a USED or NEW motor controller??
Sevcon gen4 size4 48V, 450A, part#: 4015643, VIN: 52CG6AGA6L5021311
Yes, that is what I’m asking.
Inwo, I appreciate your suggestion. I would like to leave these GEMs as OEM as possible so that the next person responsible to troubleshoot this car won’t be in a pickle trying to figure out this change. I simply volunteer my time here at this Retirement Community to work on projects like this, but won’t be here for long (not that I’m kicking the bucket, rather I’d be moving on)…so someone (?) else will have to pick up where I left off, hopefully with the manuals and online help guiding 'em.
Any 2016+ sevcon controller will plug and play. As far as running well enough to test. A new Polaris controller will not, nor will vcm swap.
Check on forums and Ebay.
I may or may not have asked for you on my facebook page. Gem 2016 performance group.
AssyRequired, I don’t know how I missed this msg from you, but just noticed it. Tomorrow I will check on this suggestion to see what the PackV does across B+/B- as I press the pedal. I will also put a camera on the controller LED as I’m doing this to check if the LED flashes while in process and before possibly resetting,
I did notice that pin1 on the controller (+48V switched power input) does sort of a momentary reset (drops and comes back on), but I don’t recall at this moment at what point it did that. Definitely worth a check tomorrow. like I mentioned already, these batteries are factory and it is a 2020 GEM…that makes these batteries 6yrs old! so…
As far as pin 1.
Pin one comes direct from “controller relay” from B+ at main contactor through main disconnect plug.
Relay is controlled through 12v from key, bmc, and vcm. I know this, because my controller kit requires hotwiring direct from key control.
If there has been any probing done at 23p plug, suspect female contact stretching. Your issue seems to happen too often and regular for that.
just reached out to him and he no longer has it available. he has opened a GEM parts store (online) and is a possible for a new controller though. it might be that he and I are misunderstanding each other during our FB chat, but he is under the impression that he couldn’t simply program the new controller and send it to me, rather he states that the new controller can only be programmed while IN THE CAR. he did say that he will look further into it before committing.
Tomorrow I plan on checking precisely on this. I will let you know afterwards. Thanks.
Yes, a dealer needs to program in the car. I can clone a new one to yours on the bench. 90% sure! It’s been a while.
Do you know what a new $500 controller cost from a dealer? 
A $500 controller?? I don’t know what you mean. this is what GEM of Miami parts listing likes like…
…and the pricing seems to be similar across other stores online, all unprogrammed.
ok, obviously it is I that is still confused. I was understanding that the VCM and the BMC have to be programmed together and ON the GEM associating the VIN, the Battery Pack, Accessories, etc. and can not be swapped out individually to other GEMs. But the Motor Controller, once programmed can be swapped to another GEM (so long as the specs match; model/voltage/amps) successfully without worry of rejection or conflict…continuing normal operation. Maybe the key phrase is “once programmed”?
So, if I need to replace this controller in TX with a new controller from a source/store that is across the country, in FL…how do I order a brand new controller and then install it if the store/tech is not on site or anywhere close to my location? I do not care where or from who I order the controller from, if once purchased it could be shipped to me and I can plug it in to get this car to drive.
The dealer will probably use his program Digital Wrench. This will need the physical car to plug into and info (such as Vin and car specific info) to be present. They can program a blank controller but DW needs to see all the components and all the little boxes filled out in order to be happy.
From INWO-
I can clone a new one to yours on the bench. 90% sure! It’s been a while.
(Translator applied)
INWO does not have DW, but will probably use a Sevcon (controller specific) program that has the ability to clone your old controller programming and apply it to a new controller directly.
He thinks he can do this. While normally super smart and creative, It has been a while, he is old, on 14 different medications, and forgets what he had for breakfast.
INWO:
Do you know what a new $500 controller cost from a dealer?
Translation:
Do you know what the dealer actually charges for what should be a $500 controller?
Don’t even get me started on throttle pedals!!!
All correct.
One solution for you if you are willing to blow $2k on an oem controller:
Send it to me along with you original controller and I will clone the new one to the old one. $100 plus return label. No guarantee, but refundable if controller is not correct.
Keep in mind that this is a long shot. That is, a controller failing without fault codes would be new to me.
1 Like
I am Blessed!
Through the help on this forum, this group of GEM enthusiasts assisted me through this head-scratcher of problem. Through all the suggestions what to check and eliminate, together we finally found what the problem is…a single 6V AGM battery was bring down the whole system.
I followed AssyRequired suggestion to put a meter on the B+/B- at the controller while pressing down on the pedal, this is where the 48V took a nosedive to around 45V and stayed there until KeyOff reset. Before this test, I checked the fully charged battery-pack, I was getting 48.6V and testing each battery individually (while connected and in place) they checked to be right at 6.09 +/- 0.5V. However, I removed each battery from the GEM and load-tested each, one of the batteries just cratered down to 4.?V and it was this battery that its case was ‘deformed’ but only visually noticeable when pulled away from the others. So I swapped that single battery out with another 6V AGM I have and the GEM runs!! I know it sounds like I’m overly hyped, but you have to understand this GEM had me researching 20(?) different sources on trying to understand this GEM vehicle and losing sleep over the past couple of weeks. ugh! The good news is, I know more about these GEM cars than I really care to and the bad news is I have to replace a battery…which isn’t as bad as trying to replace the controller with a new EXPENSIVE one and probably never getting a new one installed because it could not even be programmed without the programmer sitting in the GEMs seat while doing it. *heavy sigh!
Here is my next question: Currently the 2020 GEM has factory installed Leoch 6V AGMx8 batteries…IF I just replace this one defective battery with another 6V Deep Cycle AGM, say from the local battery store (but not a Leoch brand), does the BMC need reprogramming? Next question: If I replace all 8 batteries with another Deep Cycle AGM brand, does the BMC need reprogramming? with either scenario, does any module need reprogramming or is it just a simple remove the old AGMs and put in the new AGMs with nothing further to do?
Again gentlemen, thank you very much for taking the time to engage with me over this problem and helping find the solution. if I could, I’d send each of you a six-pack.
Paul
Every now and then I manage to accidentally pull a rabbit out of a hat!
Presto!
In a pinch (to get this car out of your shop and out to the parade), you can sometimes get away with replacing a single battery in a pack, but it is not considered a good fix. The pack will never balance properly and he entire pack will usually cascade into failure.
Even partial success will be determined by the condition of the remaining batteries.
Your original post did not say how old these batteries were, but I see in your very last post you hint they are Factory installed 2020 batteries??
Cr@p, I’d say he did well if they lasted 6 years!!
Replacing one battery if the others were gently used and a year old is a crap shoot. One would have to match the new battery exactly in size/age/capacity to get it to perform with the batteries already in the car. This is tough enough to do when replacing all 6 at once when they are new. Purists will try to get all 6 batteries date matched as close as possible. Even then, a user should be checking balance every 6 weeks or so. Who does that?!?!?
Your last test (B+/B- on top of the controller) said you started out with “fully charged batteries at 48.6v”.
FYI - a 48v pack at 48.6v is considered depleted and in need of a charge. (using the 50% SOC rule)
My opinion - FWIW…
>>> Stop messing around and put in 6 new batteries <<<
As long as you are replacing the batteries with same/like size/type batteries, I’d say there is no other programming of the VCM/BMC needed to keep the car running.
Right on! that is the message that I cut&pasted to the person holding the purse strings, hopefully it’ll resonate with 'em.
AssyRequired, Inwo and all others, again thank you. I pray for all to have a Happy Independence Day and have a relaxing and festive day celebrating our freedom to live the life we choose to live.
just for the record… I have asked twice.. and i did not get a response… lol.. .. Byron is awesome, Good Job Byron.!!!
just for the record… I have asked twice.. and i did not get a response
Yes, you did, and that you were(ignored). I too get ignored all the time. A previous postee said my comment was lost in all the banner ads.
Looking back on this, I try and review some of the clues that were missed that might have led to the solution quicker than 58 posts.
What threw me off was the original observation (by the cart owner) of the >pop< that was heard as the slow down was observed. This is what led to assuming there was some sort of component failure.
Internal plate failure in the problem battery? Possibly a small hydrogen gas pop inside the battery? (which usually blows the battery apart).
It could have been something (ketchup pack, acorn, or stone) in the road that was run over (not related at all).
Proper observation and accurate description is key when trying to diagnose via second/third party. The short video of what the car was actually doing was a big help for me.
I am amazed there was no low battery code set/indicated.