Ezgo RXV, Decels fast, rolls a few feet in opposite direction after coming to a stop

[Mike2015]

I have an Ezgo RXV with a Curtis 1206AC-5201 controller. The cart has a gear set installed on it. The cart will run along completely normal, until your let off the accel pedal, it then seems as if the regen is all the way up, because it stops faster/ harder than normal. Once the cart comes to a stop, it will then roll backwards 2-3'. The only faults the cart had are HPD/Secuencing fault, Controller overcurrect, Stall detected/encoder fault, Comms supervision. Anyone have any ideas of what to looks for?

[BobBoyce]

Originally Posted by Mike2015

I have an Ezgo RXV with a Curtis 1206AC-5201 controller. The cart has a gear set installed on it. The cart will run along completely normal, until your let off the accel pedal, it then seems as if the regen is all the way up, because it stops faster/ harder than normal. Once the cart comes to a stop, it will then roll backwards 2-3'. The only faults the cart had are HPD/Secuencing fault, Controller overcurrect, Stall detected/encoder fault, Comms supervision. Anyone have any ideas of what to looks for?

Either the RXV has had way oversized tires put on it, or, someone may have gone in and messed with the RPM/MPH calibration value/Current maps. If neither of these has occured, then the memory in the controller has become corrupted from a glitch on the 48V power cable. This can happen if the main + or - battery cables get disconnected or reconnected from the battery pack or controller without first safing the controller by swithing the run/tow switch to tow and turning the key to off. Remove the key until finished working on the electrical.

The cart is literally out of calibration for the tire size, and the OS/VCL cannot properly calculate motor current properly for the factory Motor Current vs RPM mapping. The factory mapping only allows up to 20.5" tires before errors in current calculations start affecting operation. Those values should never be changed unless the person changing them knows exactly what they are doing and how those changes must be integrated throughout the Motor tuning menus, which are only accessable to a Factory or higher level access programmer.

If this was done, the controller may be restorable by erasing the controller OS/VCL and reflashing it with a new replacement OS/VCL. FSIP would charge you the full repair fee to do this. Someone like me would do it for free, or at least try to. If there is any hardware failure, a reflash will not fix it.

Bob

[kernal]

Bob, He said it has a gear set on it. I took that to mean high speed gears.

[cgtech]

High speed gears will do that in a Curtis Rxv every time. That's one reason why I advise against high speed gears in that model. That is what I mean when I say you will hate the driving characteristics.

[Mike2015]

Customer has 23x10 tires installed on the cart. It also has a high speed gear set in it. Customer built cart. I had it in the shop a while ago for a front end alignment, the cart did not decel the way it is now, but always seem to roll a bit, just rolls a bit farther now. I do not believe anyone has messed with the programming of the controller. Do you think it has just continually gotten worse because of the set up of the cart?

[BobBoyce]

Originally Posted by Mike2015

Customer has 23x10 tires installed on the cart. It also has a high speed gear set in it. Customer built cart. I had it in the shop a while ago for a front end alignment, the cart did not decel the way it is now, but always seem to roll a bit, just rolls a bit farther now. I do not believe anyone has messed with the programming of the controller. Do you think it has just continually gotten worse because of the set up of the cart?

Ok, makes sense... Oversized tires AND a high speed gear set. No wonder! I'm suprised that his controller has not failed yet. That is likely why it is acting up now, on its way out... He's going to need to buy a 350 Amp Curtis upgrade controller, and have it recalibrate it to allow it to survive. Here are links...

https://shop.txtsv.com/speed-control...-12v-batteries

https://shop.txtsv.com/speed-control...6-8v-batteries

I would not even want to try tackling the motor maps for that combination, because no amount of recalibration can totally fix it to get it back in OS/VCL range with the factory OS/VCL. But the upgrade controller can be recalibrated enough to allow it to survive. It'll forever be a flatlander cart with that combination.

[Mike2015]

Thank you for the quick response, I appreciate the help, I will get with the customer and see which route he would like to go.

[ascheetz12]

Originally Posted by BobBoyce

Ok, makes sense... Oversized tires AND a high speed gear set. No wonder! I'm suprised that his controller has not failed yet. That is likely why it is acting up now, on its way out... He's going to need to buy a 350 Amp Curtis upgrade controller, and have it recalibrate it to allow it to survive. Here are links...

https://shop.txtsv.com/speed-control...-12v-batteries

https://shop.txtsv.com/speed-control...6-8v-batteries

I would not even want to try tackling the motor maps for that combination, because no amount of recalibration can totally fix it to get it back in OS/VCL range with the factory OS/VCL. But the upgrade controller can be recalibrated enough to allow it to survive. It'll forever be a flatlander cart with that combination.

I'm the client the tech was referring to. Do you have a contact number where you can be reached?

[BobBoyce]

Originally Posted by ascheetz12

I'm the client the tech was referring to. Do you have a contact number where you can be reached?

Yes I do, but you don't have enough messages posted yet for me to send you a PM (Private Message). I PM'd it to Mike so he can give it to you.

[expresscarts]

Motor speed sensor - I don't know what all this nonsense about big tires and reprogramming is but ..