Oil Pressure Switch to Oil Pressure Sensor Conversion

[tdstuart]

Edit: Please read posts in pages 1 & 2 that contain more info on part numbers and tuning changes required for this conversion. Also contains links for the best deals on parts (save $100+ on sensor & connector)

Gen 2 cars either come with an oil pressure switch (normal/low pressure) or an oil pressure sensor (reads a range of oil pressures).
The performance pack cars definitely come with pressure sensors.
It appears as though all gen3 cars moved to a pressure sensor, no more pressure switch.

What has been confusing me is that some people are putting performance pack gauges into non-performance pack cars. I have a 2015 mustang gt premium, it only has the pressure switch. I am not sure that you can put the gauges in. I am getting into contact with LMR who had a tutorial on how to swap the performance gauges into non-pp cars (tutorial).

The tutorial mentions that non-performance pack cars may have the connector for the gauges behind the a/c vents and that it is plug-and-play. Some forum members have mentioned you need your tuner to "enable" the sensor.

I am planning on wiring up the pressure sensor like the performance pack cars do and running the connection to the pcm. Then I can use my ngauge to read the pressure. I wanted to make this post asking for some community input on if you have put the performance gauges in your non-performance car and if you have a pressure switch or sensor from the factory. I also just wanted to post the wiring and part number info.

Gen 2 Switch: 6U5Z-9278-D (White, Less Performance Pack, 54MM, 1/4" NPTF)
Gen 2 Switch Connector Wiring Kit: 3U2Z-14S411-MHA
Gen 2 Sensor: CM5Z-9278-A (With Performance Pack, 1/4" NPTF) (CM5Z9D290B)
Gen 2 Sensor Connector Wiring Kit: 9U5T-14474-KA (AU2Z14S411GA / WPT1066)
Gen 3 Sensor: GN1Z-9D290-B

Gen 2 Parts Diagram (See 2 different sensors):

Gen 3 Parts Diagram:

Oil Pressure Sensor Connector C1657 (gen 2):

Oil Pressure Switch Connector C103 (gen 2):

Powertrain Control Module Connector Pin #s (gen 2):

Pin​	Circuit​	Gauge​	Circuit Function​	Qualifier​
34	LE423 (VT-GN)	20	CTRL MOD. - POWERTRAIN # VOLTAGE REFERENCE ENGINE (VREF) (E-VREF) (VREF1)	5.2L
34	LE423 (GN-VT)	20	CTRL MOD. - POWERTRAIN # VOLTAGE REFERENCE ENGINE (VREF) (E-VREF) (VREF1)	5.0L
48	CMC24 (GY)	18	SWITCH - OIL PRESSURE	5.0L
49	RE454 (YE-GN)	20	CTRL MOD. - POWERTRAIN # SIGNAL RETURN ENGINE #2
57	CMC24 (GY)	18	SWITCH - OIL PRESSURE	5.0L MTX / 5.2L

I think pin 48 is used for automatic transmissions and pin 57 is used for manual.
So since I have an automatic I would remove the switch pin at 48 (pcm) and wire up pin 1 from the oil pressure sensor to it.
I would then wire up pin 2 of the pressure sensor to the pcm pin 49.
Then I would wire up pin 3 of the pressure sensor to the pcm pin 34.

From what I am understanding is that multiple things share pins 34 and 49. I am new to wiring and not sure if you could just solder the wire into the existing wire or if there is something else going on. Any info on this would be greatly appreciated! I will have to do more research and post more info on this.

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[GavinG]

I’m currently in the process of doing the same thing. Pin 48 is used for the non-performance pack oil pressure switch, so the grey would have to go into 57. Did you just tap into existing wires for the other 2? that’s what i’m going to try to do.

 

[tdstuart]

I’m currently in the process of doing the same thing. Pin 48 is used for the non-performance pack oil pressure switch, so the grey would have to go into 57. Did you just tap into existing wires for the other 2? that’s what i’m going to try to do.

Still plan on doing it just haven’t got everything I need to.

How did you determine that pin 48 is non performance pack switch and 57 is sensor? The only different it shows is it labels 57 as 5.0 MTX/5.2. The performance pack was only offered in manual usually but I think there was a special version with an auto trans and performance pack. So I think I would lean to agreeing with you that 57 would be the correct for sensor but I also think 57 is used with manual transmissions with the switch.

As for connecting since I didn’t end up doing it can’t give any real advice but tapping into any wire connected to those pins should work I would think.

 

[80FoxCoupe]

I have a 2016 base gt and have done this, sort of...

My car was a 6r80 and have swapped to a th400. I swapped engine harnesses with a new one for a 2016 manual PP car. I did this for two reasons. It eliminated the 6r80 wiring and added in the oil pressure sensor. Oil pressure on data logs and ngauge, reads erratically. Like up and down 8psi rapidly. I'm sure there is some kind of smoothing that I'm missing. I have turned on any related oil psi selections I can find in FORscan.

 

[GavinG]

Still plan on doing it just haven’t got everything I need to.

How did you determine that pin 48 is non performance pack switch and 57 is sensor? The only different it shows is it labels 57 as 5.0 MTX/5.2. The performance pack was only offered in manual usually but I think there was a special version with an auto trans and performance pack. So I think I would lean to agreeing with you that 57 would be the correct for sensor but I also think 57 is used with manual transmissions with the switch.

As for connecting since I didn’t end up doing it can’t give any real advice but tapping into any wire connected to those pins should work I would think.

I determined that because i have both harnesses. My mustang is a performance pack already but the harness was bad, so i had to get a new harness. The new harness i got was for a manual car but without the performance package, and the grey wire was in 48. On the original harness the grey wire was in 57.

 

[tdstuart]

I determined that because i have both harnesses. My mustang is a performance pack already but the harness was bad, so i had to get a new harness. The new harness i got was for a manual car but without the performance package, and the grey wire was in 48. On the original harness the grey wire was in 57.

Good to know!

I looked into the wiring a bit more. Here is the wiring diagram. Not a wiring diagram expert but looks like you should be able to splice in anywhere for the signal return and voltage reference. Hopefully this diagram helps.

Pressure Sensor Pins:
Pin 1 [CMC24 (GY)]: Switch - Oil Pressure
Pin 2 [RE454 (YE-GN)]: Signal Return Engine #2
Pin 3 [LE423 (GN-VT)]: Voltage Reference Engine
Pin 3 [LE423 (VT-GN)]: Voltage Reference Engine

Looks like VT-GN is manual transmission specific, but as both GN-VT and VT-GN seem to run the same and both go into the pcm at the same pin I don't think that matters at all.

This also seems to show the CMC24 (GY) running directly to pin 57 for the sensor, so that seems to confirm it.

Electronic Engine Controls CC 24-4:

Edit: Reuploaded images

 

[GavinG]

i’ll probably attempt to do the switch this weekend, i’ll let you know how it goes.

 

[WildHorse]

Why mess with inferred ? Get a T coupling, and run a mechanical oil pressure gauge.

 

[tdstuart]

Why mess with inferred ? Get a T coupling, and run a mechanical oil pressure gauge.

Nice to have it on data logs and my ngauge. For other cases like GavinG he is probably just trying to get his new harness to work properly (have his pp gauges display correctly, etc.).

What do you mean by inferred?

 

[GavinG]

I did it, here’s what happened:

I routed the vt-gn through the harness, but the others were right there so no need

The car runs, idk about how good

Oil pressure gauge work perfectly, starts at 70psi and drops down to 20 at temp, but the engine reads low oil pressure.

This could be either the gauge is lying to me or the oil pressure switch is lying to me, and my bets are on the switch.

All temps are great, oil pressure reads fine on the gauge, ran the car at idle for about 15 min and no problems, drove it around the block and ran fine, no weird smells or leaks, but i have problems.

It is sending out a code that says the pcm can’t talk to a connector, could be the pcm or could be the oil pressure switch. I reved it out and got a weird noise from then on, until i stop the car and started it again.

I don’t really know whether i do have oil pressure or don’t, as i have no way of testing, but my bets are on i do, and the grey wire was spliced wrong, or the splice introduced resistance that it didn’t like.

 

[Snakebyte]

I did it, here’s what happened:

I routed the vt-gn through the harness, but the others were right there so no need

The car runs, idk about how good

Oil pressure gauge work perfectly, starts at 70psi and drops down to 20 at temp, but the engine reads low oil pressure.

This could be either the gauge is lying to me or the oil pressure switch is lying to me, and my bets are on the switch.

All temps are great, oil pressure reads fine on the gauge, ran the car at idle for about 15 min and no problems, drove it around the block and ran fine, no weird smells or leaks, but i have problems.

It is sending out a code that says the pcm can’t talk to a connector, could be the pcm or could be the oil pressure switch. I reved it out and got a weird noise from then on, until i stop the car and started it again.

I don’t really know whether i do have oil pressure or don’t, as i have no way of testing, but my bets are on i do, and the grey wire was spliced wrong, or the splice introduced resistance that it didn’t like.

Is it possible you have debris plugging up the oil psi sensor, or even worse an oil galley? It sounds like it, if you can shut the car off, then start it and the problem seems to disappear, gravity (backwards flow of oil in a galley) is moving the debris away from the constriction point.

Anyway, hopefully this will provide some insight to help you.

 

[Marin]

I did it, here’s what happened:

I routed the vt-gn through the harness, but the others were right there so no need

The car runs, idk about how good

Oil pressure gauge work perfectly, starts at 70psi and drops down to 20 at temp, but the engine reads low oil pressure.

This could be either the gauge is lying to me or the oil pressure switch is lying to me, and my bets are on the switch.

All temps are great, oil pressure reads fine on the gauge, ran the car at idle for about 15 min and no problems, drove it around the block and ran fine, no weird smells or leaks, but i have problems.

It is sending out a code that says the pcm can’t talk to a connector, could be the pcm or could be the oil pressure switch. I reved it out and got a weird noise from then on, until i stop the car and started it again.

I don’t really know whether i do have oil pressure or don’t, as i have no way of testing, but my bets are on i do, and the grey wire was spliced wrong, or the splice introduced resistance that it didn’t like.

I believe that when you change over from a pressure switch to a pressure sensor, you not only have to make the necessary wiring modifications but you also have to use a tuner to change the sensor type the ECM is expecting to see installed.

I believe this is not something that can be done via Forscan but likely needs a tune file from Lund etc.

 

[tdstuart]

I believe that when you change over from a pressure switch to a pressure sensor, you not only have to make the necessary wiring modifications but you also have to use a tuner to change the sensor type the ECM is expecting to see installed.

I believe this is not something that can be done via Forscan but likely needs a tune file from Lund etc.

Finally decided to actually tackle the project and am ordering in the sensor and connector.

Yes tune will need to be updated to tell the car it has a oil pressure sensor and not switch
Voltage for the sensor may also need to be changed in the tune, see below for pcm tec.

Gen 2 Car with Oil Pressure Sensor:

Gen 2 Car with Oil Pressure Switch:

There is also a toggle for oil level sensor:

Not sure if forescan will also need to be used or if the tune changes are enough.

 

[tdstuart]

Got a new part number for the wiring connector kit, not verified though, I called up my local dealer to get it since I don't have access to the ford wiring diagrams anymore.
Gen 2 Sensor Connector Wiring Kit: HU2Z14S411BA

Edit: Doesn't look right. Also found: AU2Z14S411GA

Edit 2: I believe AU2Z14S411GA is the correct connector, will probably try to verify before ordering. The connector is under the part name CE3268CL or ‎S2499. The cheapest I have found is $50, not many of these connectors floating around it seems.

Edit 3: Rock Auto actually has it for $22. (https://www.rockauto.com/en/moreinfo.php?pk=6312123)

 

[tdstuart]

Bought my oil pressure sensor on ebay for ~$13 (vs $55 from most retailers) from: https://www.ebay.com/itm/116207348337

Received today and looks good, looking at the connector end it also confirms my previous post about the connector. Will receive the connector sometime next week and will be able to verify fitment. After that I will figure out which wires I will tap into, wire everything up, load the tune, and see what happens. I will be posting updates.

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