# GEM E4 Batteries show charged but car slowly dies after 100 yard
**URL:** https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062
**Category:** GEM Forum
**Created:** [July 6, 2018, 5:11pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062 "2018-07-06T17:11:45Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 10, 2018, 5:55pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/21 "2018-07-10T17:55:58Z")
Thx. I will has to try this weekend as I cannot work on it right now due to work issues. Thx
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 15, 2018, 9:02pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/22 "2018-07-15T21:02:50Z")
I got my GE Sentry controller programmer& software back from a friend. I pulled the fault codes and I am getting an 82 fault. That code refers to “check speed sensor and wiring or motor overloaded reset motor controller”.
I pulled the speed sensor and the magnet looks good. The behavior I am getting with it starting and dying out quickly and then after I let sit it acts like a small burst then dies like the motor may be at the end of it’s life, not the speed sensor. It’s a 2008 so the motor is 10 years old with 5600 miles but was reprogrammed a few years ago to get a higher top end speed and less regeneration restriction when coasting. Here are the function code settings.
1-MPH scaling not used 0
2-Creep speed 8
3-Controlled acceleration 10
4-Max Armature Current Limit 255
5-Pluggin current limit 128
6-Armature Deceleration rate 20
7-Minimum field current 55
8-Maximum field current 255
9-Regen Armature current 50
10-Regen MaximumField Curve 60
11-Turf speed limit 110
12-Reverse Speed limit 200
14-IR Compensatio not used
15-Battery Volts 72
17-Pedal Down Field rate gain 5
19-Pedal Down Regen decel rate 255
20-Pedal Up Regen decel rate 255
21-MPH Overspeed/Top Speed Regula 255
23-Error compensation 10
24-Field Weakening start 85
25-Monitor 0
26-Ratio of Field Armature 100
13-Rolling Radiuus in inches 75
16-Gear ratio in tenths 107
18-Pedal down field Rate offset 64
My options are a new speed sensor or I think replace the motor. Is there a way to test the motor to see if it’s fried? Thanks
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### Author:  [@cheryll13](https://community.electricforum.com/u/cheryll13)
#### Post date: [July 16, 2018, 12:11am UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/23 "2018-07-16T00:11:26Z")
I found a company called S.C.S. in Cameron Park , California that can check Gem Car speed sensor and repair it or in my case it tested good and only charged to ship it back. I am now waiting on my throttle control to be checked (different company) Flight Systems Industrial Products in Carlisle, Penn. They can possibly repair (new one is nowhere to be found) . Same problem, full charge go 100 yards speed never above 11 MPH then die to nothing.Cut key off back on shows full charge on dash lights and only go 10 feet then die. I have been following your thread ,good luck
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 16, 2018, 2:40am UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/24 "2018-07-16T02:40:48Z")
Speed sensor and magnet are easy to check.
Meter pin 14.
A good tach signal will go over 5v and near zero. 4 times per motor rev.
With 12 to 1 gears about 50 pulses per tire rev.
Push car slow and steady. If it doesn’t pull down to near zero each pulse, something is amiss.
If it doesn’t go well over 5v it may need an added pull up, or 12v reg in controller is bad.
All this can be checked with sentry in monitor mode.
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### Author:  [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)
#### Post date: [July 16, 2018, 2:53am UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/25 "2018-07-16T02:53:46Z")
Check throttle control.
Rodney
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 18, 2018, 11:54pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/26 "2018-07-18T23:54:24Z")
cheryll13 - Please keep me in the loop for how the throttle control pans out.
I have limited time to troubleshoot based on my job and family responsibilities, so this is a stop and start process for me. I will try to do the speed sensor test this weekend.
Old\_houseboater - How do you recommend checking the throttle control? Thanks for your help.
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 22, 2018, 9:30pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/27 "2018-07-22T21:30:16Z")
Testing again to see if the issue is the throttle control (GEM 2008 E4 Part# 0148-01000 Assy, Pedal, Accelerator), using the instructions from Inwo thread:
“Pin 7 of the 23 pin plug on controller. Comes from the throttle box. It should change smoothly from near zero (\<1.4v)to about 4 volts with increasing throttle. Pin 3 is 2.5v from the start switch. It should go to near zero (\<1.4v) and stay there throughout range of throttle position. All tests use B- for meter common.”
I tried to test voltage of Pin7 while putting black to ground on metal and red on Pin7 reading DC V and did not get a reading while the car was on, fully charged, and pressing on gas. I tried to get readings from the controller itself and the plug that goes into it without any luck. I tried other pins with no luck. I do see the controller is getting the appropriate 72V from the battery connection. I think I am not connecting the black common correctly? Clearly I am not an electrician.
I am also assuming that the reading should come from testing the plug that goes into the controller with female connections and not the male controller pins. It this correct?
The car does not show any error codes on the dash, when I try to drive it. It will try to creep in reverse slowly, as well in forward in High and turf, and the car will only go like 1-2 MPH for a brief period then die completely. Before it dies completely, If I hold down the foot break and step on the gas giving resistance, after a few seconds the engine stops pushing, it flashes an error code of 82 on the speedometer, like I have hit a threshold, and resets. I can let go of gas, and do it again with foot brake resistance and get the same thing again. If the throttle control is bad, could it send some signal to move the car, or should it fail completely?
I can’t see to find this part anywhere for sale online either. It’s a ~$300-400 part so I want to confirm this is the issue before buying another one. Any thoughts appreciated. Thanks.
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 22, 2018, 10:09pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/28 "2018-07-22T22:09:24Z")
Chassis is floating. Use B- reference for testing the 72v system.
Testing 23p wires is easier said than done. For most tests it is left connected.
You may be safe with E-brake on, but better to have wheels off the ground.
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 22, 2018, 10:33pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/29 "2018-07-22T22:33:41Z")
Inwo,
I don’t understand what you mean by “Chassis is floating” or, “Use B-reference for testing 72V systems”. Could you provide some more detail?
I unplugged the 23Pin connector from the controller, under the hood, for trying to test voltage with a volt meter. Should I have the controller plug connected and be connecting the volt meter somewhere else, like the throttle control harness in the pic attached? 
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 22, 2018, 10:45pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/30 "2018-07-22T22:45:47Z")
So think I understand the Chassis is floating as it is not truly grounded. If I have the black and red wires connected to the voltmeter and the red touching the PIN I want to check, where should i be connecting the black probe? Thanks.
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 22, 2018, 11:01pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/31 "2018-07-22T23:01:20Z")
Did you ever get resolution on your throttle control? I’m trying to determine if that is what I am experiencing as well. Thanks. Tim
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 23, 2018, 12:38am UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/32 "2018-07-23T00:38:45Z")
The easiest place to connect black lead is B- on controller.
B- goes to throttle, speed sensor and many other places.
You can check test at the throttle plug, but I don’t know the colors or pin-out.
I’d like to get my hands on a bad throttle to learn about rebuilding them.
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### Author:  [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)
#### Post date: [July 23, 2018, 1:32am UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/33 "2018-07-23T01:32:21Z")
B- is battery- connection at controller B+ is the battery+ connection at the post.
The other oddity in GEM cars is that the 12 volt- source IS connected to the frame
This item comes up monthly. Maybe we should make it a point to include Batt - and
Batt + in our conversations. I think it would be a help to those not electrically versed
as some of us.
What say you?
Rodney
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 24, 2018, 8:54pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/34 "2018-07-24T20:54:43Z")
Rodney,
I agree. The more info the better. Sorry for slow response, I cannot access during the day at work.
Inwo,
If I find out that my throttle assemble is bad I will mail you the bad one so you can play with it. I attached a pic of one Rodney posted showing the inside.
I also am going to attach picks of the controller and plug to help when referencing pin locations.
Thanks
Tim
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 24, 2018, 10:05pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/35 "2018-07-24T22:05:08Z")
Here are pics that can be used to show controller pins and number locations which have helped me. Also the Throttle control location and opened.
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 24, 2018, 10:16pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/36 "2018-07-24T22:16:17Z")
Inwo: The easiest place to connect black lead is B- on controller.
Old\_Houseboater: B- is battery- connection at controller.
You are both saying the same thing. Which is great, although for the non-eletrician, where is B- located on the controller?
Is that referring to the Black Negative battery post that connects the controller to the battery source? or is it a pin location or plug slot?
When I uses Sentry software to program the controller, I connect a jumper pin to connect the Sentry programming plug to the controller plug into slot #1 which I believe is power. Is this where I should connect the Black post from the volt meter on the Controller Pin #1 or the controller Plug Slot#1, when testing the throttle voltage? Hope my question makes sense. Thanks.
Tim
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 24, 2018, 11:34pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/37 "2018-07-24T23:34:45Z")
B-/Battery- is connected to the big terminal on controller marked B-.
It is also the negative battery post.
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 24, 2018, 11:44pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/38 "2018-07-24T23:44:37Z")
Power off, 23p plug out, test pins 7, 8, and 9 with ohmmeter.
Ohms change smoothly through travel, testing from 7-8 and 8-9.
Use 10k or 20k scale.
Test switch from Pin 16 (B-) to 3.
Should have steady continuity throughout travel of acc.
Use lowest ohms scale.
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### Author:  [@TimFitz](https://community.electricforum.com/u/TimFitz)
#### Post date: [July 28, 2018, 10:19pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/39 "2018-07-28T22:19:25Z")
Thx. I tried electric volt meter and it just jumped all over the board, numbers would not stabilize. Then used old school needle meter and could not get a reading on Volts but using ohms connecting the 7 to 8 pin and 8 to 9 pin while my wife pushed the pedal I saw smooth needle movement at different ranges but only when touching black and red to 7 & 8 or 8&9. If I put black line on B- post of controller or pin 16, I get no reading. Same with Pin 3, no reading. Not being an electrician, I have no I idea to assess if it’s working, I am not near ant GEM dealer, so I think I am stuck with having to remove the throttle control and send somewhere to be tested. Pulling my hair out. What 's left of it…
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### Author:  [@Inwo](https://community.electricforum.com/u/Inwo)
#### Post date: [July 28, 2018, 11:55pm UTC](https://community.electricforum.com/t/gem-e4-batteries-show-charged-but-car-slowly-dies-after-100-yard/14062/40 "2018-07-28T23:55:19Z")
Close but I may misunderstand your results.
8-9 should not change. Steady resistance.
from 7-8 smooth movement
also 7-9, same but reverse movement of meter.
8-9 reads about 1k to10k ohms, steady. should not change
See the arrow on 7? Shown mid-throttle.
It gets nearer 8 or 9 as throttle is moved.
8 to 9 should not change.
3-8 is the switch
Near zero ohms when pressed, to end of travel.
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