GM often puts in the wrong gear ratio information in one or both the pcm & tcm module our software does its best to determine which one is correct sometimes its just not possible.

In any event if the calibration doesn't match what the abs module says you are supposed to have you will usually trigger an abs module code, in those cases the abs module needs to be reprogrammed closer to what the pcm & tcm think the gear/tire is.

 

I've ran into this before, I just left the gearing and adjusted tire size to best match..

 

How do I reprogram the ABS module?

 

Tech 2

 

I'll post my video up tonight. I have a video of mine doing it after adding a stall and 4.11's I've calibrated the speedometer and confirmed it with my GPS.
On the times it does it the speedo starts to hesitate, I believe it's the hesitation thats causing it. Just can't figure out why its doing it.

 

 

Same two lights on mine. After asking a million people I just took it to the dealer. If they can't fix it I'll be buying four new 245-65R17's so I don't have to deal with it.

If anyone's interested in the 265-70R17's PM me in case I have to buy new.

 

Yea. it's happening when the speedometer starts to get lazy and bounce. There's either something wrong in the calibration, cluster, or one of the sensors.

 

posted on EFILIVE. maybe they know something

http://forum.efilive.com/showthread....8982#post88982

 

All is well supposedly. The dealer is downloading the necessary tune for the setup.

Like foff667 said, the module and computer weren't communicating properly.
The speed sensor was reading the wrong speed and shutting off the abs which made the lights come on.

$50 for the GM download and another $190ish for the labor to install.

Which brings the total payment to get these tires on without dash lights to around $1200.