Brake computer message

[SLFD Fireman]

I just bought my '05 Silverado 1500 Z71 two weeks ago. I am getting a computer message "Service Brake System". When this happens the parking brake and ABS light comes on. The speedometer quits working and the truck kicks out of gear. The dealer replaced the speed sensor. I have now been stranded three times since that was replaced. My guess....that wasn't it!! Any help?

[sjspor]

Well, first I'd get the truck back there.

 

There are codes being stored from that message, and those will point a tech in the direction to go in. However Brake and and body codes won't show up on most scan tools.