if this controller is an EV100LX system then the code 93 is related to brush sensor indicator circuit

SYMPTOM
Status code flashes on and off.
POSSIBLE CAUSE
User defined status code is displayed by switch closure
or motor brush sensor closure to negative.
* See OEM instruction manual for corrective action
required.

you may want to go back in the motor brush area and double check the wires on the sensors going into the brushes. Any of them open?

if one is burnt it could be shorted on the negative side causing the code to trigger.(probably touching the brush housing?)

And of course the worse case scenario would be the TMM (if it has one) is fried.

Also just for posterity go to the fuse panel and check the fuses, if i'm not mistaken they used a fused negative circuit, usually the bottom fuse. Make sure its not open.

FYI: if it was burned badly even cleaning it up might not do the trick, i would check all the connectors and terminal ends real close, you could still have an open or very restricted continuity scenario.
AND, once you do get the motor to run IF it will, check the com bars while its running, if you hear them clicking that will be a problem also, it will trigger a code if the brushes leave the com surface while running. Once this situation happens there is no remedy, no amount of commutator work will prevent the inevitable, the armature will have to be replaced eventually.

just some thoughts to ponder on while scratching your head ;o)

That's what we thought. The motor spins perfect by hand. All readings from the motor are good.
When you max out the throttle and the brushes start to warm up, the voltage is only showing around 5 volts.
We are all out of ideas as pretty much all of the elctrical components test good according to the manual.

Are you sure that nothing mechanical is keeping the motor from turning, stuck brakes, bad gear case? Did you try to spin the motor by hand with the wheels off the ground? If everything spins free, then smoking brushes probably means something is wrong/shorted with the drive motor. The card is probably ok if it causes scr hum.