Low oil pressure warning

[TJC]

With the tank location near the firewall I need to insure the vacuum kit isn't too tall.

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[Grumpz]

Very Expensive - Shotgun of Harness
This can be fixed without it; however, it may take some deep T-Shoot to find the bad wire circuit.

With the Harness never being addressed with the Fan Clutch replacement, I HIGHLY suspect the issue is within the harness run that was pulled which is approximately 12 inches of wire.

This is a VREF Circuit and any issue along the circuit can take the circuit out, with only an Oil Press warning on the IPC, and this is the only Code showing up (Scanned) I would next go to the (Splice S152 & S156) feeding the Oil Press Switch & Variable Oil Pump.
Dependent on what code its giving.

Overall, I would say that depending on how deep of T-Shoot it takes, one should be able to locate the issue in under 4 hours due to the complexity of the integrated circuits, this takes lots of isolating various circuits.

So, it is a balance of Labor Time to T/Shoot vs Parts + Labor to Replace it.

Due to History (Fan Clutch), I truly believe the issue to be near that connector.
But to be clear, with the Fan Clutch (OE) was the hose broken and the inspection of the wire harness visually (Good)? - If (YES) I am sticking to this statement, and there is a high possibility of broken strands in that short harness run (Hidden) under the wrap.
Or did they just replace the Fan Clutch as precaution and no visible damage to the support hose?

Their techs seemed uninterested in finding the issue. After a day and a half of troubleshooting, they gave up. Ford customer service was no help and any other line I called couldn’t help me. The techs just gave up and called the Ford engineers, which basically shrugged and told them to replace the entire harness because “finding the bad wire would be too labor intensive and would cost more”. Personally, from my perspective, I’m mechanically savvy but not so much with electrical. I wouldn’t think it would take two master techs a day and a half. But here I am anyways. Wish they had your attitude but I believe it’s more about them not wanting to deal with the headache than anything

 

[Grumpz]

Very Expensive - Shotgun of Harness
This can be fixed without it; however, it may take some deep T-Shoot to find the bad wire circuit.

With the Harness never being addressed with the Fan Clutch replacement, I HIGHLY suspect the issue is within the harness run that was pulled which is approximately 12 inches of wire.

This is a VREF Circuit and any issue along the circuit can take the circuit out, with only an Oil Press warning on the IPC, and this is the only Code showing up (Scanned) I would next go to the (Splice S152 & S156) feeding the Oil Press Switch & Variable Oil Pump.
Dependent on what code its giving.

Overall, I would say that depending on how deep of T-Shoot it takes, one should be able to locate the issue in under 4 hours due to the complexity of the integrated circuits, this takes lots of isolating various circuits.

So, it is a balance of Labor Time to T/Shoot vs Parts + Labor to Replace it.

Due to History (Fan Clutch), I truly believe the issue to be near that connector.
But to be clear, with the Fan Clutch (OE) was the hose broken and the inspection of the wire harness visually (Good)? - If (YES) I am sticking to this statement, and there is a high possibility of broken strands in that short harness run (Hidden) under the wrap.
Or did they just replace the Fan Clutch as precaution and no visible damage to the support hose?

Also I mentioned for them to look at the previous repair/issue done just a year ago and they stated “found no issues with fan clutch or wiring/hose issues. Found oil in in oil sending unit/ solenoid. Replaced, cleaned wires and code went away temporarily before throwing same low oil pressure light”

 

[TomSim]

Received a low oil pressure warning on start up. Scanner revealed 5 codes:
- P06DB - engine oil pressure control circuit low
- P0034 - turbo bypass valve A control circuit low
- P06A0 - variable A/C compressor control circuit
- P2602 - coolant pump A control circuit low
- P2682 - engine coolant bypass valve A control circuit low

Gave her an oil change (some comments that oil nearing end of life could cause oil pressure issue on this engine), no joy. I also don't see any way to see actual oil pressure from PCM. I have a nice Autel MX808 scanner, the Ford app has no live data (that I can find anyway).

My first move would normally be swapping in a new oil pressure sensor but, only 12K on the truck and that's a lot of codes to all be secondary. Appreciate any experience, advice the community has on this.

its under warranty so why not take it into the dealership and let them figure it out??

 

[TomSim]

Their techs seemed uninterested in finding the issue. After a day and a half of troubleshooting, they gave up. Ford customer service was no help and any other line I called couldn’t help me. The techs just gave up and called the Ford engineers, which basically shrugged and told them to replace the entire harness because “finding the bad wire would be too labor intensive and would cost more”. Personally, from my perspective, I’m mechanically savvy but not so much with electrical. I wouldn’t think it would take two master techs a day and a half. But here I am anyways. Wish they had your attitude but I believe it’s more about them not wanting to deal with the headache than anything

demand they give you an under warranty loner and tell them to fix it or else

 

[Grumpz]

demand they give you an under warranty loner and tell them to fix it or else

lol didn’t work. “Doesn’t qualify for powertrain warranty” and I called several Ford customer service numbers, spoke to managers. Basically Ford is telling me to go f*k myself. It’ll be the last one I own. May not mean much to them but they lost a loyal customer

 

[RangerBill]

Well here I am over a year later. Fan clutch was replaced along with blown fuses and oil pressure sensor. Now I get just the low oil pressure indicator light and car eventually goes into limp mode, dealership had two master techs look it over and attempt to troubleshoot, called a Ford engineer and their solution is to replace the entire engine wiring harness which will NOT be covered under powertrain warranty and will cost me 2300 bucks with only 43k miles on this thing. I’m done with it after this, definitely trading it in somewhere.

Do you have any DTC codes for the low oil pressure? Here is the circuit for the oil pressure sensor wiring.

Here is the wiring for the variable engine oil pump control solenoid.

 

[Grumpz]

Do you have any DTC codes for the low oil pressure? Here is the circuit for the oil pressure sensor wiring.

Here is the wiring for the variable engine oil pump control solenoid.

I don’t have the codes in front of me but apparently the short/grounded/loose wire is somewhere in the main harness and not with the actual oil pressure sensor or solenoid. Thanks for the info

 

[RangerBill]

I don’t have the codes in front of me but apparently the short/grounded/loose wire is somewhere in the main harness and not with the actual oil pressure sensor or solenoid. Thanks for the info

Can you post the DTC(s)?

 

[airline tech]

If its the oil pressure switch and the VREF circuit, VFEF is complex and can be very difficult to T-Shoot, anything on that circuit and it extends farther than the posted pic can pull down the VREF circuit - but this will normally trigger multiple codes, not just a single code.
The VREF MAY require the complete circuit disconnected to isolate the fault. when I say anything this includes the sensors and the wiring.

If it is the Variable Oil Pump - Its a much more simple T-Shoot, and in this circuit a small voltage drop in the circuit could cause improper operation of the Variable Pump - which will trigger the Oil Press (code)
The reason I focused on this circuit (as I am still) not clear - I know the Oil Press Sensor was replaced (history) but was the Fan Clutch? and if it was —-Was the hose/tube damaged?
If the answer is (YES) and they have visually inspected the wiring as good - (Correct)

I am looking for a direction of highly possible hidden damage here as a few broken strands of wire (could be the root cause) and note where the Fan Clutch in the circuit vs the Var Oil Pump
and more importantly the splice (S152)


In either case I would break this out - I have this and its proven to be a great tool (expensive - kit) but it is a time saving tool.

I like this tool for the fact I can use it as a Tone Generator or Apply Voltage to a circuit and test for voltage drops along the harness run. it works great for issues like this

 

[airline tech]

With the recent post (single code) Turbo By-Pass valve after Fan Clutch - Wire Damage.
I am even more certain that S152 is the (issue location)
It is HIGHLY LIKELY - that this Splice is burned and melted and is damaged just enough to drop power (voltage drop) the power feed to the Variable Oil Pump.

The issue is its buried in the harness - may take a bit of time to get the harness opened and locate it. (approx. 1 hour) for just a hunch (possibility) but way cheaper than a harness replacement.

My - Hunch lies at S152 as a HIGHLY Suspect failure point
A test would be - check for voltage at the (3-Connectors) that feed off of that splice.
Look for a Voltage Drop (I suspect the Var Oil Pump) will show under 12 Volts

 

[dtech]

With the recent post (single code) Turbo By-Pass valve after Fan Clutch - Wire Damage.
I am even more certain that S152 is the (issue location)
It is HIGHLY LIKELY - that this Splice is burned and melted and is damaged just enough to drop power (voltage drop) the power feed to the Variable Oil Pump.

The issue is its buried in the harness - may take a bit of time to get the harness opened and locate it. (approx. 1 hour) for just a hunch (possibility) but way cheaper than a harness replacement.

My - Hunch lies at S152 as a HIGHLY Suspect failure point
A test would be - check for voltage at the (3-Connectors) that feed off of that splice.
Look for a Voltage Drop (I suspect the Var Oil Pump) will show under 12 Volts

You sir are amazing, hope you are around should I ever have an issue with my ranger

 

[scpearson1]

Thanks for the thread. I just confirmed that I had this same issue with blown 12 fuse. 2019 XLT 105k miles. Last night I picked up my wife from her office and she complained that it was too hot in the cab. Go figure. Climate control is set to auto dual side with temp set to 70. It is about 55 degrees outside. Air is blowing a nice cool temp out of my vents. She says it is blowing hot air. Sure enough, her vents are blowing warm air. I start to turn down the temp on her side until it blows cool. I end up turning her side down to 60 before the air temp changes. Not 20 seconds later I get the low oil pressure warning. Checked DTCs this morning and found this thread and replaced the fuse. I'll report back once I know more. Thanks, everyone for posting.

Update: blew the fuse again.

I had the same issue, fuse kept blowing. On inspection I found the support for the wiring going to the fan clutch had dried and come loose, this allowed the harnes to drop down and contact the water pump pully, which wore through the insulation and was causing an itermitent ground. I did not replace the support hose/thing, but I repaired the worn through insulation and tie wraped the harnes to a different support to keep it off the pully. No issue scence.

 

[RangerBill]

I had the same issue, fuse kept blowing. On inspection I found the support for the wiring going to the fan clutch had dried and come loose, this allowed the harnes to drop down and contact the water pump pully, which wore through the insulation and was causing an itermitent ground. I did not replace the support hose/thing, but I repaired the worn through insulation and tie wraped the harnes to a different support to keep it off the pully. No issue scence.

You will want to replace the fan clutch support hose, as that keeps the fan clutch from rotating (its primary function) and from pulling on the fan clutch wiring. You don't want the wiring doing the job of preventing rotation of the fan clutch assembly.

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