Interesting issue, for me anyway, 2004 TJ, 4.0 auto here. While driving the oil pressure gauge went to 0pis, Check Gauge light comes on. Pulled over and listened to the engine, no noise to indicate that there was 0psi oil pressure. Waited about 15 min with the engine running, then the gauge went back up to the center position (I know it is really an "idiot" gauge not reading true pressure) and no more issues driving home.
Once I got home, with the engine running and oil pressure gauge in the middle I disconnected the connector on the oil pressure sending unit, but no change in the oil pressure gauge it was still showing in the center. I let it run like this for 20-30 min, restarting it a few times and the gauge always read in the center each time. I then performed the instrument cluster self test and got the b0, b8 and Panel Open errors. After running this test, when the vehicle was started, with the sending unit still unplugged, the gauge then read 0psi. I plugged the connector back on the sending unit with the engine running, the gauge still read 0psi. I then restarted a few times, with sending unit plugged in, and the gauge stayed at 0psi. I ran the instrument cluster test again (sending unit plugged in), got same errors, then restarted and the gauge went back to the center.
My plan is to remove the instrument cluster and clean the connectors behind it, but are there other connectors that I need to look/clean?
Once I got home, with the engine running and oil pressure gauge in the middle I disconnected the connector on the oil pressure sending unit, but no change in the oil pressure gauge it was still showing in the center. I let it run like this for 20-30 min, restarting it a few times and the gauge always read in the center each time. I then performed the instrument cluster self test and got the b0, b8 and Panel Open errors. After running this test, when the vehicle was started, with the sending unit still unplugged, the gauge then read 0psi. I plugged the connector back on the sending unit with the engine running, the gauge still read 0psi. I then restarted a few times, with sending unit plugged in, and the gauge stayed at 0psi. I ran the instrument cluster test again (sending unit plugged in), got same errors, then restarted and the gauge went back to the center.
My plan is to remove the instrument cluster and clean the connectors behind it, but are there other connectors that I need to look/clean?