# Jerking in fwd and rev does not drive **URL:** \ **Category:** GEM Forum\ **Created:** [October 19, 2023, 12:26am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068 "2023-10-19T00:26:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 12:26am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/1 "2023-10-19T00:26:01Z")
Hi guys, new to Gem carts. I have a 2016) E4 that barely inches along and sounds horrible in either fwd or rev. With front tires off the ground the cart front wheels spin fast. Under load/on ground nothing. Do I have a bad motor? ![TC_00844](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/7/73287f3ce81d4587f3fcde6d0629fc533654b900.jpeg) ---
**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:** [October 19, 2023, 12:28am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/2 "2023-10-19T00:28:33Z")
Make sure encoder is plugged in solid. And encoder is not loose. Flat 4 wire plug from motor. ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 12:39am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/3 "2023-10-19T00:39:51Z")
Yes it is 100 plugged in. ---
**Author:** ![And1939](https://avatars.discourse-cdn.com/v4/letter/a/4bbf92/32.png) [@And1939](https://community.electricforum.com/u/And1939)\ **Post date:** [October 19, 2023, 1:16am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/4 "2023-10-19T01:16:33Z")
I have a similar problem Mine runs after i push it or spin the tires. I am trying a new speed swnsor ---
**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:** [October 19, 2023, 2:49am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/5 "2023-10-19T02:49:52Z")
See if it’s the same with sensor unplugged. It will also do that if motor is phased wrong. Have any wires been disconnected? Any other history? ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 3:29am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/6 "2023-10-19T03:29:12Z")
Nothing has been disconnected. Newer batteries. [Video of motor out.](https://youtube.com/shorts/RS5zQabVAxI?si=UUEH_a8qouqqPHVq) ---
**Author:** ![RichardE](https://avatars.discourse-cdn.com/v4/letter/r/7c8e57/32.png) [@RichardE](https://community.electricforum.com/u/RichardE)\ **Post date:** [October 19, 2023, 8:11am UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/7 "2023-10-19T08:11:15Z")
Are the brushes in the motor sliding freely? I’ve been working on a motor where the brushes were seized solid and the buggy motion was jerky. I’ve freed up most of the brushes and now the motion is much smoother (though it might have been due to something else). ---
**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:** [October 19, 2023, 12:19pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/8 "2023-10-19T12:19:55Z")
Forgot to ask. What error codes? ---
**Author:** ![JarJarJava](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/jarjarjava/32/15158_2.png) [@JarJarJava](https://community.electricforum.com/u/JarJarJava)\ **Post date:** [October 19, 2023, 3:19pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/9 "2023-10-19T15:19:09Z")
> [@RichardE](#): > > Are the brushes in the motor sliding freely? AC motor in the OP’s gem. They don’t have brushes. ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 4:41pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/10 "2023-10-19T16:41:56Z")
Codes pop up on the dash panel? Controller had a green light no flashing codes. ![TC_00843](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/3/340314371be32f2a3b89b701a8dad05ff536f8b9.jpeg) ---
**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:** [October 19, 2023, 4:45pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/11 "2023-10-19T16:45:49Z")
Must be a Polaris problem then. What codes? ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 5:44pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/12 "2023-10-19T17:44:23Z")
I’m not sure where to find the codes? The dash panel display here only has a wrench pop up when it’s acting up. I had the motor out yesterday and it is an a/c Mahle motor. Seemed like the rotor had some play in it and did not spin freely on the stator. Put the motor back in. Today it’s at least driving 5 mph. Before it starts bucking and just stops again. ![image](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/4/4c114d097ea90ffcaa99f52131af9707b0d216a4.jpeg) ![image](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/6/6d3bd3e4fb6ae33ed6eecc82a497f9a73037d4c1.jpeg) > [@Inwo](#): > > Must be a Polaris problem then. What codes? ---
**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:** [October 19, 2023, 5:47pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/13 "2023-10-19T17:47:53Z")
Select with the button to display fault codes. ---
**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:** [October 19, 2023, 5:50pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/14 "2023-10-19T17:50:12Z")
Sevcon errors clear when powered down. Look for code immediately after car bucks. ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 5:50pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/15 "2023-10-19T17:50:59Z")
I did only wrench pops up. ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 5:54pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/16 "2023-10-19T17:54:57Z")
![IMG_3233](https://canada1.discourse-cdn.com/flex030/uploads/electricforum/original/2X/7/73be2032b4cd7cb08cbc9a3d3a933f74dc3542e3.jpeg) Okay I have code 6? ---
**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:** [October 19, 2023, 6:03pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/17 "2023-10-19T18:03:28Z")
Over current or ground fault. All I can think of is to disconnect phase wires and meg them to frame. ---
**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:** [October 19, 2023, 6:11pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/18 "2023-10-19T18:11:48Z")
I saw your video when you had the motor out. That motor only has one bearing on the far end and is supported on the spline end by the gearbox input shaft bearing. It looked like what you were doing was perfectly normal. Your vid showed/sounded like you were moving it to the side far enough to catch the speed/hall sensor. When your display is showing Veh Fault (and or the wrench) you should be able to scroll through them with the Mode button. ---
**Author:** ![312Bear](https://avatars.discourse-cdn.com/v4/letter/3/b9e5f3/32.png) [@312Bear](https://community.electricforum.com/u/312Bear)\ **Post date:** [October 19, 2023, 6:33pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/19 "2023-10-19T18:33:42Z")
Found out how to get the fault code to display. Here is the code: 520518: 6 ---
**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:** [October 19, 2023, 10:09pm UTC](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068/20 "2023-10-19T22:09:49Z")
Same code. You might try driving with phase wires disconnected. See if it throws an open circuit code. [Next page](https://community.electricforum.com/t/jerking-in-fwd-and-rev-does-not-drive/27068.md?page=2)