2008 GEM, error codes

My GEM sat up for a while i have since recharged all of the batteries and got it running. problem is on ignition the screen just start blinking all of the lights and logo and i get error code 8 when i press the pedal i get error code 11. sometimes when i get it to run it looses speed and doesnt recover. i have to turn the key multiple times to get it to drive and it will kill on me or just lose speed. i do have sentry software and programmer. its a T3 controller. any help with a fix would be much apreceiated!

So you got the batteries to hold a charge but have you validated they have any capacity?
If they are any type of lead based batteries then you should see a steady state voltage of ~12.6V each and right after a charge they should be at over 13V for around a half hour after you remove the charge.

To really validate the battery capacity you can do a “brake test” where you put a volt meter on a battery, turn on the GEM, put the brake on and put a slight pressure on the throttle peddle and observe the voltage of the battery. It should not drop below 12V and good batteries should be able to hold up around 12.5V with a slight load. Repeat that for each battery.

Sounds like you might have dead batteries which only hold a surface charge and any load quickly drops their voltage.

The batteries were replaced in 2020 AGM DEKA . I pulled them all out and charged them individually. my battery light on gem shows full charge. when i turn the key on i dont hear the “click” sound like it is in gear even if it has been charging overnight.i will try the voltage test to eliminate that as an issue.

The Main Contactor (main relay) will not engage until a few safety checks are passed.When KeyON, what does your dash panel show?

Are there any error codes displayed? A yellow wrench indicates the controller has an issue. The big number will be an error code.

The car will not move until the brake is released. Is there a red Brake Warning on the dash?

With all errors cleared, the pedal needs to be depressed a bit, THEN the main relay will snap closed.

This is first issure

This is the other issue

Error code 8 is when i release the brake, 11 is when i press the pedal, nothing happens.

im just noticing the brake light says on, do you think it may be the brake switch?

What do you do to get/respove the First issue? (flashing dash).

That is associated with a controller/communication issue.

The 08 is a Throttle pedal voltage mismatch issue.

These could be both related to bad connections on the big 23 pin connector on the top if the controller. Make sure it is clean, tight, and try the KeyON again.

basically cleaned all connectors with contact cleaner, the flashing dash comes and goes , right now its the 08 and 11 issue, but like i said i notice the brake light is on even when the parking brake is released.

if i use the Ge sentry software will it help pinpoint the issue? i have the software and manual.

if i use the Ge sentry software will it help pinpoint the issue?

Possibly, but you need the special dongle that allows a usb/serial connection AND have the controller connected at the same time. do you have this?

but like i said i notice the brake light is on even when the parking brake is released.

Yep- I caught that, but the red light is a third tier problem compared to the other two issues. The dash flashing being most concerning. The nature of it “comes and goes” is not a good state to be in. It sounds like a bad connection in that plug or on the PSDM. That will be the next place to check.

Have you gone through the troubleshooting tips in the manual? It describes checking pins by probing the plug with your meter.
If you have not yet, Don’t do this. The very nature of sticking your meter probes in that 23p connector tweaks the contact springs in the female pins and is the cause of many future problems.

Brake light
If you want to work backwards then OK. What is the level of your brake fluid? There is a level sensor in the side of the reservoir that can trigger that light. Unplug that sensor for now and see if that light goes out (Y/N?).

Next- to check the Park Brake loop you should KeyOFF and drop the handbrake. The dash should Steady Beep. (Y/N?)
Lift the brake or KeyON will silence the Beep.

I have all of the sentry equip and software not sure how to work it

Fluid is low , unplugged sensor light went off

Still gives me 08 and 11 codes, brake switch works bc it beeps when off

Fyi i do know how to hook up sentry stuff and read and write to controller just not sure how to use it to troubleshoot the controller

Great. Now we can focus on the 8. (Ignore the 11 for now).
The actual code description is as follows:

-08 Accelerator voltage input is too high on power up after initial key switch

When this happens it is usually because the Pedal Ground has a bad connection. This is also related to the 23p connector. The throttle pins are 7, 8, &9. Look at those closely.

It looks like you have the programmer cable that replaces the car harness plug on top of the controller. For the Sentry aspect you need a double ended T-adapter that goes inline with the car harness.

Yes the cable i have replaces the harness on the top of the controller and you just plug a pin into the #1 female harness attached to the cart . it allows me to program the diff parameters adjusting for bigger tires and motor. didnt adjust much. but didnt know there was another harness to run diagnostics. im going home to individually test all of my batteries. the blinking screen has seemed to disappear after i cleaned the controller connections with contact cleaner. will check the throttle pins also, is there an actual ground wire i should be looking for?

My battery test results. Has to be accelerator imo.

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good news i filled brake fluid reservoir back to max and the brake light went off on dash. is there a place i can order a replacement accelerator for a 2008 GEM?

No, The Pedal Harness gets ground reference within the controller. You can check at the pedal plug. Did you check yet?

  • Pin K should be B-
  • Should have 5v on D when Ref K
    (I have the purple dust shield off for this pic. You will need a small needle to get in past those thin slots)

Has to be accelerator imo.

Don’t jump and call this as a pedal issue until you check for proper voltages and connections. You HAD a bad connection at the controller (flashing display). Hopefully you have that 100% fixed. Now check those other pins.

The Fem pin/sockets in the Controller 23p plug are quite finicky. they have 3 wipers spaced around the socket that lan on the male part. If you look closely on the controller they are actually square pins. Once these wipers get a little tweaked out of position (from inserting a meter probe) they may not land fully on the square pin the next time.

With a nice light and some good loops, inspect the sockets and make sure you can still see all the little wipers. Take special note on 7, 8. & 9.


I would not consider this(the car not runnng)as a battery issue at this time, but since you presented it here in your diagnostics it is worth mentioning .

Be skeptical of results and what your capacitive tester is telling you. Sure- anything can come out with good report if you don’t enter what the target CCA is supposed to be.
Note that it looks like it is default to 100 cca. If the battery is rated for 550 then you are in the green. If 600 then only two of them are good. Without knowing I wouldn’t take this as positive proof. Look on the label or look up what your batteries are actually rated for, enter the number into the meter, then run the test again (for your education). It is possible to have voltage on a battery and no capacity when loaded.

What batteries are these? even 600 CCA seems a little small.
For reference, a quick search pulls up the following-

Deka 9A31 AGM Intimidator Battery
Group size: 31
Cold Cranking Amps (CCA): 925

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