Gears and tune

Mike_S

OOPS!
Nov 18, 2009
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In my mind, I just seems more correct to make the ECM recognize the correct gear ratio first, and then correct the pulses per mile. Perhaps this won't work on all trucks, it has always worked for me, but more and more it seems like these damn trucks are very tempermental, and have each got a personality of their own. LOL!

Interesting note however, at least on a snap-on scan tool, it does read 4 independent wheel speeds...however I don't recall weather or not the 2 rear wheelspeeds read identical all the time or not. Makes sense they would have to being as the only speed sensor for the rear wheels is on the transfer case.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
In my mind, I just seems more correct to make the ECM recognize the correct gear ratio first, and then correct the pulses per mile. Perhaps this won't work on all trucks, it has always worked for me, but more and more it seems like these damn trucks are very tempermental, and have each got a personality of their own. LOL!

Interesting note however, at least on a snap-on scan tool, it does read 4 independent wheel speeds...however I don't recall weather or not the 2 rear wheelspeeds read identical all the time or not. Makes sense they would have to being as the only speed sensor for the rear wheels is on the transfer case.

hmmm, really wish i knew the ECMs process. Im gunna PM Ben about this. maybe he knows how it goes about figurin out your speed.

so what would a 2wd need to do:confused:

same as above. only your VSS is in the tail shaft housing. The front WSS are at the hub so gear change does not affect them
 

05' Ditry Duramax

New member
May 3, 2008
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Port Orchard Washington
All I know is that you need to reflash the ABS module to get the ABS light off. I know Pat posted this info over on DP a LONG time ago. You have to reflash the module with tire size calibrations from the Kodiak. Have I done this? No......a few guys at the dealership couldn't figure it out. As soon as I put gears in my truck the lights came on.

The ABS module turns the light on because it's getting 2 different speeds. One speed from the VSS and another speed from the ABS sensors in the wheel bearings. The module or ECM (whatever it is IDK) freaks out and thinks something is wrong because of the 2 different speeds. Sorry, that's a really bad way to explain it.
 

05' Ditry Duramax

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May 3, 2008
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i wish EFI Live could re-flash the abs contol mod. would make things so much simpler

That would be nice. I kinda gave up on getting mine done. I couldn't find anyone that knew how to do it. I'm sure it's simple but of course trying to talk to guys who take their time very seriously is tricky. I think a dealership has to be in the medium duty (Kodiak) service to pull anything from TS2000.