This engine light was second (same) issue as the first, but this time an NO2 Sensor was defective. The part was ordered and my dealer did not get the part timely, using strike of GM as delay! I had called GM regional office to complain of delay getting part but the part magically appeared 1 day after call. Coincidence or what?? Part replaced Dec. 8, 2019!

I dared not go far prior to repair for 1 day over 1 month in an $81,000.00 brand new truck! The danger in trip was no knowledge of when the truck would go into 55 mph limp mode and then no knowledge of when it would go into 4 mph mode which deprived me of my new trucks use!! It was all OK for several short runs, only in town less than 4-5 miles and very near help if needed. After the repair, I thought all was right, this was the way a new truck should behave finally!

This is 3rd time for same issue according to On Star diagnostic code given to me when it happened. They got the same service rep as before and their diesel mechanic on holidays until after 2020 starts. They would run superior to On Star diagnosis again Dec. 23, 2019 and then fix when the diesel man is back. There is no date because he is already heavily booked! Here I am again deprived of my $81,000.00 new truck used for all, except in town for 4-5 mile trips. I dare not risk highway miles because of unpredictability of going into limp 55 mph mode and then the same with the 4 mph mode.

The full diagnosis is needed but it is now going to be a huge scare to take it on a trip. I bought the truck as my main vehicle for all my uses, especially a diesel to tow a small 7250 lb. Travel Trailer. I have not been able to use my trailer since coming back from Canada where I did tow it to and back. The first engine light issue came on there and had a flash for new software and regeneration to get the light set to normal.

I was home several weeks and again the light came on. It was the same diagnosis but this time a sensor was detected as bad. See my notes previously describing my frustration of not being able to use my truck. It now looks like I am going to be approaching 2 months of not using my truck!! I certainly will be scared to use it for a trip of any kind now that 3 engine light issues in same system has occurred! What can I do to get a truck I can feel secure to go places in?

I am 80 years old and would like to be able to use my also new at same time $40,000.00 Travel Trailer? At 80 years old, you don’t plan very far in advance for a trip that you desire to take!! Help, anyone? I should have bought a Ford diesel. I have had 3 Super Duties in the recent past with none of them ever being in the shop except oil changes and regular maintenance. I chose the GMC because it was a 2020 whereas the Ford Super-duty diesel would have been a 2019! Pride won and I picked the GMC! I did not know GM has had many issues in the past with the DEF system ever since the Duramax has been available. Engineers reported they had no fix!!! GREAT!