Service 4WD

[smtaylor]

2009 GMC Yukon SLE, Have looked on internet and other boards for this and have read all. Haven't seen much on this board with this subject. Last year "Service 4WD" came on in my display when I switch the selector to AWD, 4HI or 4LO. When I change the selector, it will blink for the selected option for 5-10 seconds and stay on. Also the "Service 4D" will appear in the DIC. When I switch back to 2WD, the selector will switch back with no blinking for the 2WD option and no DIC display. I have pulled the fuse and checked and replace after about 5 minutes (some suggested this). Have changed out the selector switch in the dash. My questions - When pulling the fuse to reset the TCCM, should the key switch be in the on position or running? Also, should I have the TCCM reflashed or replaced?

Thanks for you time

 

[PaulS63]

Do have access to a pro level scan tool ? I 'd look for stored codes before any other action. I once had a service traction control message. There was a TSB on this regarding extreme cold temperature, they reflashed it and it's never happened again.