I have a 01 dually auto and today I turned into my driveway and my dinger went off, my check gauges light came on and I had low oil pressure. I got out checked the oil it was fine so I started it back up oil pressure was normal then went back to being low again. I turned it off then restarted it and it work normal again. I think it might be the sending unit. Any help to what the problem might be would be great.