12200411 PCM swap for 1996 to 2000 GMT400 trucks
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AK49BWL
GMT400 Forever!
The only thing that goes to the cruise module from the PCM is the VSS signal so I'd verify you connected those two VSS lines together to the one output on the PCM. Factory PCM has two VSS outputs, 0411 only has one so you have to tie your two factory VSS wires together.
Rey Del
Newbie
How ya doing ?
Me and “Babe”(1997 5.7 vortec,4l60e 4x4)
Were hoping to do the 12200411 swap with your kind shared knowledge that you have in that spreadsheet of yours.
Wich I will risk my money time and effort in whatever it takes for you to share with me in hopes of performance mods with “babe” I’ll appreciate your time in some sort of reply
and as a good man to an awesome man here’s my email so we can chat about it
[email protected]
L31MaxExpress
I'm Awesome
I had my old laptop with Tunercats OBD2 and some older black box tunes I read open earlier. As I remembered the are HUGE discrepencies in the MAF flow curves between an 01-02 van and a 96-2000 truck or van. When GM changed the airbox on the vans to the 01+ newer style the MAF curves changed dramatically. They all 3 use the same MAF part number. The Mexican GMT800 L31s use the LS truck 85mm MAF and LS airbox, the GMT800 L31 has the same MAF curve as a LS or even 8100. Makes perfect sense why I have seen 0411 swaps with double digit positive fuel trims and often P0101 codes. The MAF curve is completely off base. I will post the curves later.
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Supercharged111
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Don't forget about F body MAF curves too. Crazy how the same MAF performs so differently on different air box setups.
L31MaxExpress
I'm Awesome
Y-body is different yet again. The B/D cars also have a different MAF curve than the 4.3L V6 yet again too. The B/D car L99 and LT1 have the same smaller MAF as the 4.3L.
Good idea though, look at an Astro tune between black box and 0411 or P59. Those had the same intake tract and MAF from 1996 to 2005. Wonder if GM kept the same curve there.
I wonder how much of the difference in the Express van curves is the revised airbox vs how the PCMs read the MAF. The Express vans have a very tight 90* plastic coupler at the exit of the MAF and the nose of the MAF sits in the end of the round filter.
The blackbox data is limited to 11,000 hz atleast in my Tunercats OBD2 files where the 0411 tune has a high maf value of 12,500 hz.
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L31MaxExpress
I'm Awesome
Well looking around I had a HPT file for a 1998 Black Box and a 2003 P59 L35 Astro. The MAF curves fit practically over the top of each other. The couple of places the frequencies match are exact as well. The 1998 Blackbox curve stops at 11,216 hz with 357.70 gms/sec and the P59 is 362 gm/sec @ 11,250 hz and GM flat lined the curve at 362 gms/sec at higher frequencies. Not like a 4.3L is getting anywhere close to that anyway. That knowledge however tells me that yes, the MAF curve needs to be reworked in an 0411 van file to run in a GMT400 correctly. The MAF curve in the 0411 in the 01-02 vans is specific to the goofy air box they ran.
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