Need help again!!!

[bdr2008]

Let me start with sorry but I need help again. Every tune that I try to put in my LB7 truck screws up the trans. It don't limp it, the first tune I put in made it sorta go into neutral when it down shifted from second to first. ONLY SOMETIMES. The second and third tunes work great but after 5 or 10 miles it down shifts to third and trips a trouble code on the TCM P0735. It says wrong 5th gear ratio. What am I missing. I am posting my stock tune and mod. tune if anyone can help that would be great. I WILL FIGURE THIS EFI OUT even if it kills me and my truck..

[DmaxHawk]

Does it do the same thing even on a stock tune?

[bdr2008]

No it is fine with the stock tune..

[mijdirtyjeep]

P0735 usually means "Irregular 5th gear ratio" and is normally associated with toasted C3 clutches... the reason you do not get the code on stock setting, is there is not enough power to limp the tranny "YET" once you limp it it will be easier to do everytime thereafter.. Looks like it is time for a rebuild

[bdr2008]

When it did this I was at cruising speed and hardly no load on the trans.

[bdr2008]

I just noticed that the file size between my stock and mod. tunes are differant could there be a problem there?

[GMPX]

Depends when you read your stock tune. When we released the Full Flash on the LBZ / LMM the .tun file sizes did change. There is no need to re-read your stock tune by the way since this change.

Cheers,
Ross