hi all ...iam new to GMTNATION from TRAILVOY ,i have an older gmc 03 envoy xl sle and i just want to let everyone share my problems with the abs brakes. The innitial problem was the brakes were very spongy so i replaced the pads and the rotors thinking that was it , no way they were still spongy so i took it back to the mechanic and after acouple of hours he said it was the vacuum booster unit (about a 400$ job) here in Canada. Time for another opion so i took it to master mechanic and they tested it and cam up with a abs pressure control module failure error as it turned out that was the problem (1300$ Canadian parts and labor ....would like to hear feedback from trailblazer and envoy owners as i hear this brake problem is common........thanks all great site ...hommer