I was on a road trip up into the mountains (mountain pass just over 11,000 feet in elevation on the way) with my family and after reaching our destination town which was at roughly 8,000 feet elevation, (give or take a few hundred feet), I got a CEL. I went to the local auto parts store to borrow a code reader (I forgot mine at home) and it showed the P2BAA code, along with the "Service Catalyst Reduction System" error message on the DIC, as well as the dreaded "xx miles to max speed of 65 mph" and the DEF/SCR light was illuminated too. I cleared the CEL with the code reader but the DEF/SCR light stayed on, as well as the countdown of miles. There were 2 or 3 Ignition cycles from the time it started until when the miles remaining reached around 35 to go before reduced speed, and the DEF/SCR light turned off. 2 days later, on the way home, same thing happened again. I sensed some feeling of hesitation at certain times, and all of a sudden, the CEL and DEF/SCR light came on with about 110 miles to go to get home. The difference this time is that I did not have a code reader and we were not planning to stop anywhere on the way. I decided to get off the interstate on the way home when the remaining miles until reduced power was 6 miles. I took an exit ramp, came to a complete stop on the right side of the offramp, and turned the vehicle off, got out, locked it ... waited for about 10 to 20 seconds, then got back in, started it, and it now showed 5 miles to reduced power. When the message flashed 3 miles until reduced power, the DEF/SCR light turned off, and all was apparently back to "normal" again, except the CEL was still on, and I was not going to clear the code this time in order for it to be active when I went to the dealership Monday morning.
I get in the Equinox Monday to head to the dealership after a windshield repair appointment, CEL still illuminated ... but when the Equinox was brought back to me after the windshield repair, OF COURSE the CEL was gone! I took it to the dealership anyway and showed them photos of the gauge cluster/DIC to prove what was happening, as well as the 2 emails I received from OnStar caused by the CEL.
My wife and I have both had an issue with the DEF/SCR light (poor DEF quality and/or Service SCR system) coming on in certain situations, both alerts disappear on their own. I use Blue DEF Platinum, so I highly doubt my DEF quality is bad, and I have no problems using it in my 2018 Cruze Diesel with the same engine. I have seen elsewhere that the DEF injector itself could be bad, which would make some sense. Faulty sensor may make the vehicle think DEF is of poor quality if the system expects more than what the injector is providing.
Either way, Gus-Gus (that what my wife named it, cuz it kinda reminds her of the chubby mouse in Cinderella) is going to the dealership on Thursday (5/12/22) to see if they can pinpoint the cause of all this BS. I'll update this thread when I get some functional results.
My question is ... does anyone have any ideas what would cause the perceived hesitation I felt (not sure if it was engine or transmission) in a diesel?
