Correct Spedo For Larger Tires

[dobby]

Do you have to make changes in ecm and tcm to Correct Spedo for larger tires.

[markap81]

Only the ECM.

[dobby]

Is this true for the 2008 models. (only make changes in the PCM).

[camcojb]

I change the tire revs in both just because, but I think it only uses the ecm info for the speedo. The tcm handles the shift points, lockup, etc. yet some info does not have to be correct for it to work; for example, the trucks come with a 3.73 rear and every tcm I've looked at lists the gear ratio at 4.10 on the stock file.

Jody

[bar836]

do you have the ability to change the tire pressures for the monitoring system with the EFI Live?

[camcojb]

do you have the ability to change the tire pressures for the monitoring system with the EFI Live?

no, needs a Tech II.

Jody

[bar836]

Jody - I was at the dealer and was told that they could not change the tire pressures, that it wasn't adjustable with thier software. Is someone BS'ing me?

Thanks

[camcojb]

Jody - I was at the dealer and was told that they could not change the tire pressures, that it wasn't adjustable with thier software. Is someone BS'ing me?

Thanks

they adjust mine at the dealers, as I had a tire swap as part of buying the truck. Either bs-ing or the guy had no clue, it's done through a Tech II.

Jody

[bar836]

What vehicle are you running? I have an 07 3500. He said it only started that they couldn't adjust that parameter at the 07 LMM.

[camcojb]

What vehicle are you running? I have an 07 3500. He said it only started that they couldn't adjust that parameter at the 07 LMM.

07.5 2500HD 4X CC