abs lights with new gear ratio

[Hondo29]

I have an 06 LBZ with 38" tires. I re geared with 4.56 gears to compensate for the tire size but now after about 5 miles the abs lights go on. I didn't have an issue before the gears even with the tires. I figure since the rear speed sensor is on the tranny and the fronts are on the wheel that the computer thinks the rear is going faster than the front. What can be done to fix this? I am sure there are others that have changed gear ratios.
Thank You

[FBJR]

Did you tell the PCM that you have a new gear ratio with a programmer or have it reflashed at your dealer?

I had the wrong size programmed and the ABS light came on. Even the ABS would come on during normal braking.

Putting in the correct ratio is a must.

FB

[Heartbeat Hauler]

...Putting in the correct ratio is a must.

FB
Not to mention the 38" tires....;)
JP

[Hondo29]

I have a bully dog but they only program for tires. I have called Edge and they only program for tires also. I will try the dealer next to see if they can program for ratios. As far as correct ratio, 4.56 is back to factory rpm and speed.

[FBJR]

You may be able to comp for both the gear change AND the tire size with just tire size, but it may be more trouble than it is worth.

I wuld just get a programmer that does what you need or have the dealer reprogram it for the right gears and then adjust the tire size.

So far I have not found a programmer that gets the speedo right. I always have to comp for it and then I verify with a radar gun and GPS.

FB

[DmaxMaverick]

The dealer (or anyone with a Tech II, or compatible scanner) can calibrate the PCM for the gear change and tire size. It will not change the speedo, but will calibrate the ABS function. Several programmers can calibrate the speedo for the gear and tire size, but they do not calibrate for the ABS. The ABS sensors are at the wheels on the front, and at the output shaft on the rear, so you will have a confused PCM without a calibration.

[Hondo29]

Thank you Dmax that is what I needed to know if it can be changed thru the dealer. All programmers now only change speedo for tire size but not gear ratios. I have already fixed the speedo by changing my gear ratio. The speedo is not the problem. Like you said the abs is confused because it thinks the rear is going faster than the front.

[WhiteTruck]

The dealer using a Tech 2 can only reprogram for factory available options. Since the only gear available is a 3.73, you are out of luck. There are options for tire sizes, but not for a 38" tire. Aftermarket will be your only hope. The EBCM (ABS brake controller) can be changed to different STOCK tire sizes, even if not an option on the truck. This doesn't require a reprogram, just a option change with the Tech 2.

[Buck]

What if he uses H1 hummer calibration. They have Dmax/Alli with 37" tires.....

[Uncle Wally]

I would look into EFI live.

You can program for any size tire. I'm not sure about gear ratios though.

Not only that, but you can change your fuel/timing maps too. The same software works for both gas and diesel.

John Kennedy has some sweet tunes for the diesel. I'm not sure who does the gas stuff.

I use it on my diesel and have been very impressed thus far. It's cheaper than the other stuff per vehicle, I get a scanner and I can control a ton more than what the tech2 can. I'm currently running a mileage tune in a 4dr dually and am consistantly knocking on 20mpg with no load. Best tank mileage of just over 22mpg. And I'm not done yet!

Waldo

[FBJR]

The Diablo does BOTH the gear ratio and the tire size.

Plus they can write a program and email it to you if you need more tweeking.

FB