skbuzzard

I have a 2003 Silverado 4x4 2500 hd with a 6.0. Just to note, the weather lately has been less than 10 degrees. The check engine light came on the other day while driving, everything seems fine after I shut the truck off it hasn't come back on. Then the service brake system indicator came on after driving for about a half hour, shut truck off, it hasn't came back since. The latest is I notice it shifting somewhat hard and the transmission hot indicator is on. Turn off for about 15 minutes and the message is gone and it shifts fine. Is there one module or something that might be sending erroneous codes/messages? I tuned it up about 8 months ago and had the trans filter changed about a year ago, brakes are fine. Seems that once the truck is warmed up things are good. Any suggestions?