I have a 94 ez-go textron 36 volt electric cart. It has gotten slow.Once out of about every 50 times we use it , it seems to do fine , but the other 49 times it is super slow. I replaced all the batteries, which the local repair shop suggested,and no difference. Slow even on a full charge. Has alot of trouble backing up an incline and going up hills. Took to shop again and they said they would have to start replacing things starting with the computer , then the motor , & etc.. I don't think they may know what they are talking about. It has the F-R lever down by my knee ( which was replaced by the shop because it wouldn't move at all). Can it be put in diagnostic mode, and if so, how do I do that , and what do the codes mean? PLEASE HELP!!!!!!!!!!!!!!!