JD 444j electrical problem

[Spiva Const]

My 444J has an error code of 100.4. This code is engine oil pressure open or short. The dashboard gauge module shows no movement on the oil pressure gauge or any of the other gauges after the initial check mode when the key is turned on. All gauges move to the right stops and the red lights light up on initial test cycle then return to a random position. I checked the harnesses to the dash module and the other controllers behind the panels on the right side of the loader. There is no apparent rodent damage or frayed wires. I applied die electric grease to all the connectors.
I’m looking for some best guesses as to where to start, possibly replace the dash module or engine controll unit.

 

[heymccall]

If it's like my 544J machines, it's not the dashboard. As for the random positions on the gauges, on mine, the fuel gauge always works, but all the others stay at full off.
Haven't cured mine yet, but, I'm certain that mine has a harness integrity issue from the engine module to the machine? module.

 

[mg2361]

How about posting a serial number?

 

[Spiva Const]

My fuel gauge also works but none of the others. Something new is the alarm buzzer and light flashed just for a second twice in a short period of time after that is when the code popped up. The oil level is fine.

 

[Spiva Const]

View attachment 211169

 

[Spiva Const]

This is the second part of the error code. I guess I’ll have to find a wiring diagram. The loader only has 2,500 hours on it, all the harnesses look like new.

 

[heymccall]

Forgot to add, mine was next to a house that caught fire. All the external plastic melted, and, I suspect, so did part of a harness.

 

[partsandservice]

With that code, your oil pressure sending unit or the wiring between the ecu and the oil pressure sensor are is likely bad. As far as the guage in the monitor is concerned there are no wires that directly connect the oil pressure sensor to the monitor. The resistance in the oil pressure sensor is detected by the ecu and that information is transferred to the monitor on a CAN (data) line.

 

[mg2361]

For the code, what P&S ^^^^^said. Did you say after the initial bulb check that your other gauges do or don't work?

 

[Spiva Const]

The only gauge that works after the initial test is the fuel gauge. I have visually looked at the wiring harness and it appears ok, no rodent teeth marks. I used to own a JD544 that quit just out of warranty and after many hours the JD mechanic discovered it was a bad terminal connector at the controller. I guess I’ll try to check them next. The loader runs fine so it’s hard to stay motivated to find the problem but things like this bug me. Being old school where a guy with some mechanical skill could fix a tractor I find all the new electronics very frustrating.