Hello, our fork lift on the farm just started acting up yesterday. The check engine light came on and now it dies after a few seconds of running. I pulled the codes off it and got 933 (trans temp overheat) and 521 (low engine oil pressure). I tried clearing codes and they come back even after the fork lift sat overnight so its not overheated or anything like that. The Doosan mechanic came today and hooked up the laptop but all he told me was what i already knew. He said it might be the sending unit or the computer. Its just strange it happened all at once. After he left i got the the codes 711 and 712. I believe it was from him unplugging wires and trying things.

Any ideas or suggestions would be great thank you