My 2004.5 duramax {lly} took a crap on me. so i found a used under 100,000 miles engine from sw engines they say its an lb7 and it was compatible to swap with my lly. so now my issue is when i put the truck into drive it goes into 1st as it should then after about say 10 seconds it goes into nuetral then hits hard into 3rd and thats all i have. Then throws p0700 fault code (3rd gear limp mode i believe) fluid is full hooked a better diagnostic reader to it. with research i did thinkink the tranny had to (re-learn the engine? idk any advice will help willing to try anything at this point (besides having to remove my engine again and yada yada thanks for reading appreciatye you all for the help!
Transmission Issue?????
- Thread starter Treeasy
- Start date
My 2004.5 duramax {lly} took a crap on me. so i found a used under 100,000 miles engine from sw engines. they say its an lb7 and it was compatible to swap with my lly. so now my issue is when i put the truck into drive it goes into 1st as it should then after about say 10 seconds it goes into nuetral then hits hard into 3rd and thats all i have. Then throws p0700 fault code (3rd gear limp mode i believe) fluid is full hooked a better diagnostic reader to it. with research i did thinkink the tranny had to (re-learn the engine? idk any advice will help willing to try anything at this point (besides having to remove my engine again and yada yada thanks for reading appreciatye you all for the help!
ive checked and double checked for bent pins in the harnesses. what do you mean by shortblock?
Merged your two threads. No need for multiples for the same issue.
A "shortblock" is the basic engine assembly without heads, turbo, fuel system, etc.
Did you use the entire LB7 engine or did you put your LLY heads and turbo on the LB7 block?
Methinks you just dropped the LB7 into your LLY truck without changing any tuning? You very well could have all sorts of incompatibility issues.
A "shortblock" is the basic engine assembly without heads, turbo, fuel system, etc.
Did you use the entire LB7 engine or did you put your LLY heads and turbo on the LB7 block?
Methinks you just dropped the LB7 into your LLY truck without changing any tuning? You very well could have all sorts of incompatibility issues.
i took the turbo power steering pump and a couple other things not the heads though. basically used entire engine.
They have different injectors among many other things.
Also, youre going to have to get a scanner that can read TCM codes, as the P0700 only tells you there IS a code. We'll need that code(s) in order to help you figure this out. Most of us are tired of guessing.
the truck runs great fires rite up drives great in third lol
ok i had a guy hook up a better scanner i will have to see if he still knows the codes that tripped. im tired of guesding as well lol whatever i can do to help you all is a help to me
so he didnt remeber the code but he does remember that it said (pressure control silinoid E stuck closed)
This has got to be a troll. How could an lly FICM run lb7 injectors?
I wouldn't be surprised if it could. There is little difference between the coils of both injectors.
IIRC, there was only one volt difference between the two.
The specifications says the LB7 is 96 volts and the LLY is 48 volts. But my testing shows they both look like they operate at 96 volts, or like you said, within a volt or so of each other
Then there is that old I've seen the impossible thread on the other forum where someone did basically what we see here except the opposite where they used the LB7 electronics to run an LLY top end. Apparently it worked with the right tuning
well thats cool, no troll here just a bassackwards hillbilly, semi mathmatyical dude
Would you mind taking a pic of the driverside of the engine? Im real curious if it is a lb7 lol
Be surprised how many people get the rpo codes wrong still
Be surprised how many people get the rpo codes wrong still
This is my speculation too. I'm guessing it's actually an LLY all the way through
I just remember the original thread about the differences back at DP, where Ben found LB7 96, LLY 95, LBZ 48. OR, I could be wrong. Wouldnt be the first time.
Im still pulling my hair out if anyone has any other suggestions. Is there any way to just delete or go around this issue?