When the car is locked up, put your meter between terminal SC and LOM on the top card which is the Power card. If it is 0 VDC then the cars Low oil timer has expired. you can reset by putting car on inspect then back to normal. with the car reset the LOM test point will read 5 VDC. Check this first if LOM is not expired let me know and i will look at the board prints and try to give you another way to go. If it is in the LOM condition start looking at the usual MLT solutions. bad contacts in the hi speed valve circuit , car jerking off during relevel etc. You can also run the car from the bottom to the top removing the hi speed coil and see if the car will make it to the top, there is a pot on the power card that adjusts the LOM time.
