L5P programming injector trims with Hp tuners ecm

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
Has anyone successfully programmed injector trim codes on a L5P with an Hp tuners ecm? I have a friend's truck that was taken to a shop for a misfire and an injector was replaced and a snap on used to change the trim codes, but they all went to zeros and now will not allow it to be programmed. I'm not sure if this is because of the Hp tuners ecm or does an MDI II need to be used to correctly program the injector trim codes. Trucks far away from me or I would hook up my MDI and give it a try.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,743
5,911
113
Phoenix Az
sounds like it will need the MDI to do it. Wheres he out of? close to me at all?
 

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
sounds like it will need the MDI to do it. Wheres he out of? close to me at all?
It's in Loomis Ca, the shop can have someone come with an MDI but I wanted to see if any knew for sure that would fix it. I could plug into my dad's truck and double check but it's raining in CA and I might melt :) and also, I don't want to screw his up if for some reason the hp tuners ecm doesn't let you change the trim codes for some reason.
 
  • Haha
Reactions: Chevy1925

1FastBrick

Well-known member
Dec 1, 2016
2,600
1,117
113
Junkyard
It probably has something to do with the HP tuners modified programing. I am curious if they will be able to reprogram the injectors with the MDI. I don't believe it will do the Security Handshake required since it was modified.
See Item number 2 in the notes from HPT about there modified ECU.

Screenshot L5P HPT.jpg
 
  • Like
Reactions: juddski88

1FastBrick

Well-known member
Dec 1, 2016
2,600
1,117
113
Junkyard
Maybe HPT has the ability to do the injector coding in there newer version of software. Hopefully he has access to HPT.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,674
1,941
113
Mid Michigan
Id be contacting HPT about this first and see what they have to say about it. Would really suck to brick that ECM accidentally.
 
  • Like
Reactions: Bdsankey

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,735
804
113
Texas!!!
I would not be at all surprised if the trim codes weren't transferred over correctly in the first place. It's really not a big deal to be honest.
 
  • Like
Reactions: juddski88

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
I would not be at all surprised if the trim codes weren't transferred over correctly in the first place. It's really not a big deal to be honest.
Only problem now is that when they tried to do it with the snap on it changed the injector codes to all zeros and the truck has a CEL on
 

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
It probably has something to do with the HP tuners modified programing. I am curious if they will be able to reprogram the injectors with the MDI. I don't believe it will do the Security Handshake required since it was modified.
See Item number 2 in the notes from HPT about there modified ECU.

View attachment 111402
Number 3 and 5. I know the MDI II worked to do the anti theft relearn so I would assume it should work to do the trim codes, but also a snap on should have worked as well 🤷🏻‍♂️