2012 Cat 314d lcr oil pressure low electrical issue

[Owenfred]

Hello,

Serial ssz00549

Machine is new to me.

Display shows engine oil pressure low error in red letters at the home screen. The diagnostic menus show pressure measurements are within spec.

It appears there is a discrete oil pressure signal coming in to the display. I believe this is my issue. I'm trying to diagnose, but the schematic from the manual I bought was wrong. Anyone help with some diagnostics or a schematic please?

Thanks

 

[Nige]

Try using the diagnostic menu to show the Code for the Error you have. See attached.
I'll forward you a copy of the electrical schematic.

Do you have an Operation & Maintenance Manual for it.? If not it would be a good thing to have.

 

[heymccall]

For a tiny bit of wrenching, you could try swapping the oil pressure sensor with the fuel pressure sensor. #5 & #5A.

 

[Owenfred]

That is an analog sensor. The pressures in the diagnostic menus read okay on the actual kpa, but the digital input (high/low) at the monitor reads like the pressure is low.

I do believe this ecm was replaced and that may have been when this started to happen. This was done prior to me owning the machine so I'm not too sure.

I have a cat et3 coming, but not sure that will tell me any more than I know already.

Any thoughts are appreciated.

For a tiny bit of wrenching, you could try swapping the oil pressure sensor with the fuel pressure sensor. #5 & #5A.
View attachment 254486 View attachment 254487

 

[Owenfred]

It's basically like the engine ECM at pin 58 is outputting the wrong signal to the monitor.

I did notice on one engine schematic I found that it's possible that pin could be configured as a maintenance interval for 500hr oil change?

 

[heymccall]

Just trying to help. I understand analog vs digital input. My suggestion costs zero dollars and maybe an hours worth of time. I've seen dumber, even on my 314DLCR.

How about an intermittent no start yet the rpm signal was present during cranking. Technically, it should start with either the Crankshaft or Camshaft sensor offline, accordingly to Cat service, yet, I had a bad Crankshaft sensor and a intermittemt no start.

 

[heymccall]

As for maintenance intervals, I've adjusted all of mine through the monitor.
I like a 400hr oil change.

 

[Owenfred]

No diagnostic codes. I do have the maintenance manual, but the pressures all read good. It's this digital signal that's reading low for some reason. It comes from that pin 58 on the ECM.

I included a pic of the digital status as well as the engine ECM serial numbers.

Try using the diagnostic menu to show the Code for the Error you have. See attached.
I'll forward you a copy of the electrical schematic.

Do you have an Operation & Maintenance Manual for it.? If not it would be a good thing to have.

 

[Nige]

Any thoughts are appreciated.

A Diagnostic Code, if there is one, would get you a troubleshooting procedure.
Edit: Sorry, I was typing at the same time as you were ........

 

[Owenfred]

This maintenance interval is in the ECM I believe. It would be separate from the display. Also, I just reset that to zero in the display when I did the oil/filter after I bought it.

I will likely swap the sensors, or just replace the oil pressure sensor. But it's strange pressures indicate okay by analog, but the ECM outputs a bad digital signal to pin 58.

As for maintenance intervals, I've adjusted all of mine through the monitor.
I like a 400hr oil change.

 

[Nige]

That is an analog sensor.

Sorry to tell you but it isn't. It's a PWM-type sensor powereed from the ECM by stabilized 5v. if you want to measure the sensor output you will require a DMM capable of measuring duty cycle.


I'd go with HMC's suiggestion to swap the oil pressure & fuel pressure sensors and see what happens.

I do believe this ecm was replaced and that may have been when this started to happen. This was done prior to me owning the machine so I'm not too sure.

The engine control software (module P/N) is correct and the latest available for your machine Serial Number. The engine Serial Number shown on screen is also correct.

 

[Nige]

This maintenance interval is in the ECM I believe. It would be separate from the display. Also, I just reset that to zero in the display when I did the oil/filter after I bought it.

In addition to resetting the acumulated hours after maintenance has been performed using the keypad, you can also change the "Recommended Interval". See attached.
Judging by the document reference I don't think this is included in the basic Operation & Maintenance Manual.

 

[Owenfred]

Yeah cat is proud of that sensor at $200ea. Swap looks like a great option

 

[heymccall]

How about an intermittent no start yet the rpm signal was present during cranking. Technically, it should start with either the Crankshaft or Camshaft sensor offline, accordingly to Cat service, yet, I had a bad Crankshaft sensor and a intermittemt no start.

Oh, and ZERO faults or events.

 

[Nige]

Oh, and ZERO faults or events.

The hardest ones to diagnose, right after the ones that come and go apparently at random.

 

[Owenfred]

Well tried the swap. No luck.

Also bought a new sensor this week, and that didn't fix it either.

Back to ECM at pin 58 maybe

 

[Owenfred]

I'm seeing there might be an option in the ECM to enable or disable a "warning light" for oil pressure... I cannot see this setting in my cat et. Anyone know how to check that setting or whether that is what pin 58 is all about?

 

[Nige]

I'm seeing there might be an option in the ECM to enable or disable a "warning light" for oil pressure

Where did you come across that.? Got a link.?
On the face of it not very plausible because why would there be an option to effectively disable a warning light just because it's a nuisance.?

I cannot see this setting in my cat et.

Where in ET are you looking.?

 

[Owenfred]

Re the optional lights... See screenshot.

I'll have to look through the et menus again, but I swear I looked through all the buttons.

Biggest clue is I have no codes related to oil pressure. Only that the low oil pressure is illuminated on the panel screen.

 

[Nige]

I'll have to look through the et menus again, but I swear I looked through all the buttons.

Try looking in the Configuration Screen of the menu.