# How To Fix -90 error code **URL:** \ **Category:** GEM Forum\ **Created:** [January 28, 2024, 1:23am UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411 "2024-01-28T01:23:52Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![pchost](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pchost](https://community.electricforum.com/u/pchost)\ **Post date:** [February 2, 2024, 10:16pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/21 "2024-02-02T22:16:27Z")
Sometimes you just have to think outside the box. This harness looks to be routed in an odd way, but I’ll get it straightened out. When I bought this last month, all 4 wheels cylinders leaked and ate the shoes, 3 of the batteries were overfilled, 3 under-filled, and it had some serious fiberglass cracks in the body. I stripped the whole cart down to the frame, only to find the leaking battery acid through the rear harness. I cleaned up the frame, undercoated it completely, bought new brake kit from NEV, and started reconstructing the rear harness. I painted the body, front panel, and sides black, and left the top white. Once the rear panel is fixed I’ll paint that black. I’m looking to buy 2 new front seats and recover the back. All in, I should have less than $2,400.00 invested including the $1,500 purchase. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [February 3, 2024, 1:57am UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/22 "2024-02-03T01:57:53Z")
> [@pchost](#): > > Would you have the part number for the 23 pin connector going to the controller? Mine looks nasty and I would rather replace/re pin a new connector now rather than when something happens later. I have connectors, but just order “ampseal” 23p connecto. Must be same color. They are keyed. You can order them from China with pig tails. Or, I have an auto feed crimper for amseal pins. Uploading: 17069253712548559728589507791406.jpg… ![17069254372966568520643914422603](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/b/b50ed4af12061bc88c4a3206f3aadf188389b911.jpeg) Uploading: 17069254945058707782939834823741.jpg… ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [February 3, 2024, 2:00am UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/23 "2024-02-03T02:00:32Z")
![17069256611495702693423013872939](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/f/f641ea49a1718bb63c0ad15ade55aed8a1fe85e5.jpeg) ---
**Author:** ![pchost](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pchost](https://community.electricforum.com/u/pchost)\ **Post date:** [February 5, 2024, 11:49am UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/24 "2024-02-05T11:49:21Z")
I need to get me one of these! ---
**Author:** ![ncdotmike](https://avatars.discourse-cdn.com/v4/letter/n/ecccb3/32.png) [@ncdotmike](https://community.electricforum.com/u/ncdotmike)\ **Post date:** [March 30, 2024, 10:05pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/25 "2024-03-30T22:05:30Z")
I had a -90 code after an update to the ECU. I guess it was updated from a T1 to a T2 then the -90 code popped up. Turns out the motor temperature sensor was the problem. I unplugged the two wires grey wire and terminal 21 and plugged them together and issue resolved. Runs 33mph now. ---
**Author:** ![AssyRequired](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/assyrequired/32/7621_2.png) [@AssyRequired](https://community.electricforum.com/u/AssyRequired)\ **Post date:** [March 30, 2024, 11:02pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/26 "2024-03-30T23:02:23Z")
Nice job @ncdotmike. This illustrates the value of the archives. If you have a problem, most likely someone else has also had the same problem. A well documented thread with a proper clear solution is worth gold in most common cases. ---
**Author:** ![Moorenycc](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@Moorenycc](https://community.electricforum.com/u/Moorenycc)\ **Post date:** [August 30, 2026, 3:23pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/27 "2026-08-30T15:23:22Z")
Good morning, I wanted to jump in here to ask the best solution to this issue. I too have the - 90 code after a recent T1 to T2 swap. There are multiple suggestions in here. What is the easiest way to correct this issue? ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [August 30, 2026, 3:47pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/28 "2026-08-30T15:47:02Z")
> [@pchost](#): > > jumper from pin 2 to pin 21. There is now no delay in the pedal response and best of all, no error code 90 I am not familiar with that error code, but you need this jumper in any case. IMO ---
**Author:** ![Moorenycc](https://avatars.discourse-cdn.com/v4/letter/m/b3f665/32.png) [@Moorenycc](https://community.electricforum.com/u/Moorenycc)\ **Post date:** [August 30, 2026, 5:07pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/29 "2026-08-30T17:07:08Z")
I was able to find an old harness in my pile of GEM parts and depin an extra pin for spot number 21. Once I jumped pin 2 to 21, the -91 code went away and it’s running like normal again. Thank you for the helpful thread! ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [August 30, 2026, 6:41pm UTC](https://community.electricforum.com/t/how-to-fix-90-error-code/27411/30 "2026-08-30T18:41:34Z")
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