mistergmc

After working with the dealership for 6 months and GM customer care for 3 weeks, I have decided that I won’t risk the safety of my family on a persistent brake problem any longer. Now that GM part shipments are slow, if not completely stopped, due to the strike, I’m not going to wait it out for a new master cylinder. I have traded my AT4 in and won’t give GM any more of my business. My sincere thanks to those on this forum who have offered valuable product information. My thanks also to the leadership of this forum for making a valuable resource available. With Regards.

Add me to the list of those with a '19 AT4 and "Service Brake Assist" issues. Dealership has been trying to track my failure down since 7/19. Finally, this week, they say that GM wants them to replace the master cylinder. Now, the big wait is for parts especially with the strike going on. I've had a case open with GM Customer Care for the last few weeks.

Years back, after seeing the swirls left on the paint from using the car grinder wash, I started washing my own ride. Start with Meguires Gold car wash and the "two bucket" method for washing. Their other products are amazing and have been using them for 20+ years. If you're not as precision as myself, use the touch-free ones as mentioned above. Keep in mind though, touch-free can't remove the "haze" dirt from your ride. You'll need to put some elbow grease in at some point or take it to the wire-brush washes.

I had my AT4 in for repair on this and the software update was not enough to fix. Dealer swapped out the SD Card socket due to reports from GM that *some* were fitted with defective SD card slots on the assembly line. If you still have trouble, have them check. the socket.

Agreed. My first stop after picking up the AT4 was the local parts store. I picked up a black after-market shorty and did not look back. No noticeable affect in FM reception, however I do live in a flat metro area. Also, I spend little time listening to terrestrial stations anyway (either SXM or Pandora on cell).