2015 LML Delete Tune Problems DSP 5

ryankruger

New member
Feb 15, 2023
7
0
1
So I recently did a full delete and tune on my 2015.5 LML. I installed the DSP 5 switch at the same time of tune, instantly got a PO193 FRP code. Getting a DFRP of 5656.56 and actual FRP of 31908.8. These numbers do not change on scan tool, even if sensor is unplugged! Have it eliminated down to DSP 5 Selector switch is wired wrong or ECM is junk. Does anyone know which pins the switch should be wired in for the 2015.5 LML? The instructions from my tuner say to wire to:

2011-2016 LML: Gray ECM connector J3
Pin # 11 & pin # 35

Every other thing I can find online say the switch should go to 27 and 46 for this year LML.......wondering if this might be cause a malfunction in the ECM if the tuner's instruction are indeed wrong?

Please help as of right now I am $550 in the hole from trouble shooting plus hors of shop time! Have tried getting a new tune file sent and re-flashed. Bought a clean factory tune back to verify the ECM, changed FRP sensor ect. Tested wires, jumpered to get low fuel reading on scan tool from ECM and pressures stayed at a fixed reading.

Thanks Ryan
 
Last edited by a moderator:

2004LB7

Well-known member
Dec 15, 2010
6,988
2,146
113
Norcal
As far as I know the LML doesn't have a true DSP switch. It's wired to trick the ECM into thinking the fuel temperature is high and thus reduce power. How it reduces power I don't know if it drops the PW or reduces the fuel pressure, but I suspect the latter. You need to do as James suggested and remove the switch and test it again
 
  • Like
Reactions: ryankruger

ryankruger

New member
Feb 15, 2023
7
0
1
has no one just disconnected the dsp to see if it has any effect on it?
That is what I am going to do today. See if I can read FRP then.

Since this is only tricking truck into thinking has high fuel temperature thus limiting power, I am curious if this would effect fuel economy ect.

Also wondering whybmost of what i am finding online they call the tune for LML A. LSP 5 as opposed to a DSP 5 which is what my tune is labeled. Is there a difference?

Crazy thing is that the tuner's instructions say to wire to pin# 11 and 35. One of them is blank and other is a wire for oil pressure sensor. Everything else I can find online say it should be pin # 27 and 46 which are both fuel temp sensing lines which makes sense. If all this is due to mis printed directions from the tuner, they will be getting some advertising from me for sure!

Thanks!
 
Last edited by a moderator:

ryankruger

New member
Feb 15, 2023
7
0
1
As far as I know the LML doesn't have a true DSP switch. It's wired to trick the ECM into thinking the fuel temperature is high and thus reduce power. How it reduces power I don't know if it drops the PW or reduces the fuel pressure, but I suspect the latter. You need to do as James suggested and remove the switch and test it again
Does this temp.sensor way of controlling the HP. I was under the impression that the 5 tune levels included ideal Trans shifting ect according to the power level ect? Kinda seems like a work around....

See my reply to Chevy1925 as I included more info on pin selection ect...
 

2004LB7

Well-known member
Dec 15, 2010
6,988
2,146
113
Norcal
Since it's using the factory settings for fuel temperature so whatever shift strategies the stock tune uses is what the "DSP" tunes will use
 

ryankruger

New member
Feb 15, 2023
7
0
1
Since it's using the factory settings for fuel temperature so whatever shift strategies the stock tune uses is what the "DSP" tunes will use
Do most get a transmission tune file also then or is it a non issue? So the only thing that is changing with the 5 settings on the DSP 5 tune is the HP due to the fuel temp? I could see how that could reduce power but how does the truck have increased HP from factory id the only controlling factor a fuel temp reading would have is to reduce the power? Must be more to it than that? Sorry for the questions, just trying to understand what the tune is actually doing!

Most importantly I have to get that fuel rail alarm to clear! Hoping it is just the wrong pin number due to bad direction from my tuner and it didn't mess up my ECM!
 
Last edited by a moderator:

2004LB7

Well-known member
Dec 15, 2010
6,988
2,146
113
Norcal
The tuner only makes one tune, basically your big tune and then the "DSP" pulls the HP down via the fuel temperature compensation tables.

Traditional DSP tunes actually had multiple tables that the DSP would cause the ECM to switch over to. The tuner could load different timing, PW, fuel pressure, etc into these tables and achieve actual different tunes.

On the LML DSP I don't think you really are getting the benefits of timing changes for things like an economy tune

Most don't mess with the transmission tune as for 99% of things it's really not needed. But there are some that want different shift strategies. Sometimes things like a tight or loose converter, larger tires, different rear end or turbo can change the shift points just enough to make it not quite right. But you really have to be looking for something specific on the shifts before looking at a transmission tune
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,714
776
113
Texas!!!
As far as I know the LML doesn't have a true DSP switch. It's wired to trick the ECM into thinking the fuel temperature is high and thus reduce power. How it reduces power I don't know if it drops the PW or reduces the fuel pressure, but I suspect the latter. You need to do as James suggested and remove the switch and test it again
It's actually just an adjustable fuel limiter. It sets up the ECM to see a certain position on the switch as a certain fuel temperature and sets a maximum fuel quantity that correlates to that fuel temp value.
 

ryankruger

New member
Feb 15, 2023
7
0
1
It's actually just an adjustable fuel limiter. It sets up the ECM to see a certain position on the switch as a certain fuel temperature and sets a maximum fuel quantity that correlates to that fuel temp value.
Thanks you so much for the info! So beings all my research has said to use pins 26 and 47 which ARE the fuel temp sensors I think I should switch to them and pray it didn't mess my ECM up!

The direction I got from the tuner say to use pins 11 and 35. One of them being the oil pressure sensor. I believe this sensor can also contribute to the FRP code which is P0193. I am thinking that the tuner depot directions are wrong. I think I might pull the wires all together and then put back in the fuel temp pin holes 27 and 46.
 
Last edited by a moderator:

2004LB7

Well-known member
Dec 15, 2010
6,988
2,146
113
Norcal
Is the pin on the oil pressure sensor a ground, signal or supply wire? If it's a ground that might make sense, but not for the others.
 
  • Like
Reactions: ryankruger

kidturbo

Piston Tester
Jul 21, 2010
2,539
1,375
113
Somewhere On The Ohio
www.marinemods.us
No guru with the LML's for certain, but know the fuel temp tables and functions in others years fairly well. Use that for my oil temp sensor mod. Most likely it's because switch wired to wrong pins is killing the regulator circuit. Should be using the same 2 wires the factory sensor used. At least is how Fords wire DSP5 in there. Your just changing the voltage / temp values read in the tables.

If that doesn't do it, possibly a fat finger mistake in table: {B1083} or {B1084}. But since your commanded is much higher than actual, I'm still saying wiring related. I had a switch come loose and made me think my CP4 was failing.. Made me feel like a noob when I spotted the error on a scan tool watching the sensor voltage jump...
 
  • Like
Reactions: 2004LB7

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,714
776
113
Texas!!!
Pin 11 and 35 on the X3 ECM connector should both be open. If you had to remove wires, you're either in the wrong pin location or in the wrong connector.
 

ryankruger

New member
Feb 15, 2023
7
0
1
No guru with the LML's for certain, but know the fuel temp tables and functions in others years fairly well. Use that for my oil temp sensor mod. Most likely it's because switch wired to wrong pins is killing the regulator circuit. Should be using the same 2 wires the factory sensor used. At least is how Fords wire DSP5 in there. Your just changing the voltage / temp values read in the tables.

If that doesn't do it, possibly a fat finger mistake in table: {B1083} or {B1084}. But since your commanded is much higher than actual, I'm still saying wiring related. I had a switch come loose and made me think my CP4 was failing.. Made me feel like a noob when I spotted the error on a scan tool watching the sensor voltage jump...
So I found my problem and it was stupid simple after hours and $$$$$ it ended up being the FRP sensor pin (36) which is next to the 35 that the directions say to use, the keeper got broke so pin could push back out when put on the ECM male pins. No wonder I wasn't getting actual feed back! I had barely noticed it was 1/16 set back from other pins in plug. Glad to get it fixed but was pretty stupid simple issue. Ayleast I learned my trucks wiring well!
 

ryankruger

New member
Feb 15, 2023
7
0
1
Pin 11 and 35 on the X3 ECM connector should both be open. If you had to remove wires, you're either in the wrong pin location or in the wrong connector.
So I had a buddy helping me so wasn't 100% on what he started with as I only help land the pins after he had started. Turns out after inspection yesterday that they WERE both open BUT that is what the directions say to use. Beings I am leaving for a trip today I just pulled the selector switch wires out for now and will get them in when I return.

I think i will land them in the fuel temp sensors location (27,46) instead of what the directions say as I don't think 11 and 35 eing open would do anything for the HP control! Can't believe their directions are wrong though! Wtf
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,714
776
113
Texas!!!
So I had a buddy helping me so wasn't 100% on what he started with as I only help land the pins after he had started. Turns out after inspection yesterday that they WERE both open BUT that is what the directions say to use. Beings I am leaving for a trip today I just pulled the selector switch wires out for now and will get them in when I return.

I think i will land them in the fuel temp sensors location (27,46) instead of what the directions say as I don't think 11 and 35 eing open would do anything for the HP control! Can't believe their directions are wrong though! Wtf
It depends on how the tune is setup. If the tuner says to use pins 11 and 35, you should probably use those pins.
 
  • Like
Reactions: 2004LB7

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,681
5,835
113
Phoenix Az
So I had a buddy helping me so wasn't 100% on what he started with as I only help land the pins after he had started. Turns out after inspection yesterday that they WERE both open BUT that is what the directions say to use. Beings I am leaving for a trip today I just pulled the selector switch wires out for now and will get them in when I return.

I think i will land them in the fuel temp sensors location (27,46) instead of what the directions say as I don't think 11 and 35 eing open would do anything for the HP control! Can't believe their directions are wrong though! Wtf
as josh said, start with what the tuner said first. dont cause yourself more headache than needed
 

kidturbo

Piston Tester
Jul 21, 2010
2,539
1,375
113
Somewhere On The Ohio
www.marinemods.us
Glad to hear you got it sorted. Those secondary locks can be tricky, and as you've learned, sometimes are the only thing keeping the pins fully seated.
It is possible to reassign input pins within a tune file. I would inquire with the tuner as of why. First guess, is easier than asking someone to remove the existing pins from connector and replace with new wires. So again, I would do some research and figure out if the pins listed are correct. On the fords, ya just unplug the fuel temp sensor, and plug switch into the harness, in place of the actual sensor...
 
  • Like
Reactions: juddski88

Dirtymaxx5134

New member
Sep 28, 2023
2
0
1
Michigan
Hey Guys so i just recently did a tune on my 2015 lml. Mine is not the 2015.5 so i am not sure if it is the same, But the dsp5 switch instructions i received specifically instructed gray-pin#11 which should be the Top row closest to the firewall i believe right next to a yellow wire. and Black wire to pin 35 which will be the 3rd row. Starting pin on edge says 33then 34-35. Should be the 3rd open spot on 3rd row. Also videos I watched guy used a 16 inch drill pill to pop the plastic plug in pin slot. he did his from the inside of the ecm plug. From my experience the other day, that way is kind of shit unless you have too. I did not have the best visibility and believe I busted the internal plastic tab that hold the wire pin. I found it was better to just set tip of drill bit on the back where wires penetrate plug. You can see the bottom of the hole where it is plugged, I just held the drill bit straight and gave a light tap with the handle of screwdriver. This allowed the drill bit or 1/16" punch to only touch the plug and not the plastic locking tap. If anyone knows how I can fix this that tab inside the ecm plug that'd be great. But I managed to get everything very tight zip ties back up and looking like factory. Once I wired in and hooked battery back up I check switch for power and light function. Switch I believe is brightest in level 1 and most dim in 5.