po804 code

slc lly

hotrod diesel
Jan 12, 2010
5
0
0
today while pulling a nieghbors truck out of a snow drift the truck limped and set a p0804 dtc code im assuming its the tranny [ats st 3 with 14000 miles since installed] as its been acting up lately usually throwing a 0735 code during full throtlle 4-5 shifts my question is what is the 0804 code and is my trans in need of a rebuild already? what would be my best option for getting this looked at and resolved? does mike L do ats work?
 
Jul 31, 2009
76
0
0
Sacramento, CA
P0804-- 1-4 Upshift (Skip Shift) Lamp Control Circuit Malfunction - I'm not sure what would cause this.

P0735-- Gear 5 Incorrect ratio - If I remeber correct this often time means you sliped your clutches.
 
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slc lly

hotrod diesel
Jan 12, 2010
5
0
0
been doing some reading on atf and saw that aftermarket clutches do better with dex lll and ive been using royal purple max atf should i do a fluid change? i change the spin on every 6000 miles. as it sits now i cant drive my truck the way i want to so i need a resolution anybody got any ideas?
 

Mike L.

Got Sheep?
Staff member
Vendor/Sponsor
Aug 12, 2006
15,681
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Fullerton CA
I don't believe that is a valid code for the Allison 1000. What are you reading codes with?
 

slc lly

hotrod diesel
Jan 12, 2010
5
0
0
So i need to hook it up to a tech-2 or would efi work? do i need to get the truck to limp or will it just know? sorry man dont no much at this point about the allison other than i paid alot for mine and it isnt handling the power im currently at. Its holding back all other plans for the truck.:(
 

Cougar281

Well-known member
Sep 11, 2006
1,821
259
83
St Louis, MO
EFILive will work. If the codes haven't been cleared, they should show up as history, even if the truck is operating normally right now.

So i need to hook it up to a tech-2 or would efi work? do i need to get the truck to limp or will it just know? sorry man dont no much at this point about the allison other than i paid alot for mine and it isnt handling the power im currently at. Its holding back all other plans for the truck.:(