ok guys here is the low down. have a friend who is trying to help a building get there car back, car has been down for 2 months. original problem was bad cpu board, the display was bad causing a problem, the repair shop replaced the lcd screen and sent it back to them. the first company could not get the car off of ERU. so owner hired a 2nd company which then got a new cpu board, installed, and same problem. now a third company was hired, the 3rd company ended up getting new software, original software was AAL, new software is AAM suffix. now the car says EPC. the 4th company is now hired, my friend. he is pretty good on otis equipment, but can't get this one figured out. he says he cannot clear the EPC. he can disconnect the car from ocss, and run the car from the mcss manually, car runs fine, as soon as he enables the ocss again, EPC. he says if he takes it to the top and turns it on it will come down, but will stop on the way down in different places, sometimes almost making it to the bottom. if he sets it floor level at bottom, and turns it on, the doors remain closed, and on EPC. any ideas i advised him the owner should probably get otis over there to fix it, but he wants another day to give it a go. any ideas guys thanks

EPC is emergency power correction run I would check the floor tables an parameters that changed with software upgrade.

Look for tip 1.1.14.1.9, I can't find mine.
Is load weighing connected to OCSS or MCSS/LMCSS?
Did he try pulling the disconnect while bypassing the auxiliary contact to see if ERU functions properly?
Is ERU ENABLE set to 1?
Is he getting 24.6 volts on the ERU battery?
Does the door open button function when it's on EPC or ERU?

seems it thinks its on building emergency power and is looking for its park floor. If the building has E power then you might have lost the input from the building.
in the OCSS you can turn off the E power software under the emergency section.
255 disables

I just realized you have battery lowering so my post was wrong.

he put new batteries in the ERU. 26 volts. he tested eru, and with power off and switch jumped, display indicates ERU. the door open button will work. he said he did check the normal power wiring and input, it is not wired to the rs board. says eru setting is set to 1
as soon as he tries to go to normal he gets the EPC condition.
guess he will check all the parameters to see if he can find something strange.

Look in the cpu input for gnp. That is the normal power input. If it is low, try unplugging the hall link then the car link then the group link to see if it will go back to normal. There could be a remote dragging the link down. Line terminators can cause this problem too.
eru and EPC are both power related issues. Is the contact in the disconnect or an add on switch? I would check those switches too.
With that many different people working on the same problem. I would definitely go through all the parameters. AAL to AAM shouldn't be that much difference. Same problem with both version?

What voltage is he getting from the following

PS-244 to PS-243?
PS-248 to PS-247?
J1-12 to J1-13?

Is there a mrspc contact between PS-247 and J1-13?

Jumpers J13 or J14?

I agree. The gnp input needs to be GNP (active) not gnp (inactive).

well its running, my buddy stopped by to check on the job number for otis, to inquire about getting software, the owner hired someone else to work on it, the software had been changed since my friend was there, and it was working. thats all the info he gave me. so not sure what happened , probably software, maybe the new software was not set up properly. who knows, its running thanks guys