ABS warning light with new gears????

[twentythree]

Hi Guys,

 

I need some help, I just picked up my Suburban from my local 4x4 shop they changed my gears from 3.73 to 4.56, the guy at the shop said the ABS warning light was on because I changed my tires without transferring the factory air pressure sensors (which has its own "service tire sensor" warning) this sounds like BS to me.

 

Does anyone know enough about changing gears to tell me what in the process would affect the ABS system and what to do about it? I really didn't care about the tire sensor warning but the ABS thing is two big warning lights + I might need to use the ABS system one day.

[chevroletmb]

the computer uses a speed sensor in the transmission and or t-case to calculate rear wheel speed with the programmed rear gear ratio. now that you have changed gears the math doesn't add up. the pcm will have to be reprogrammed with the new gear ration.. not sure but i think some of the aftermarket programmers can do that.