NHTSA Complaint #11666997 — 2019 CHEVROLET BLAZER

At startup, I would receive a message that said, steering assist reduced. There were no check engine lights or warning lights. My air conditioning stopped working, and my temperature gauge on the dash remained at cold. I also noticed the radiator fans were on full blast, continuously. I called the dealer, and they weren't sure what was causing that. I told them I was getting codes #U0401 & P0128. They asked me to clear the codes to see if they returned. I cleared the codes, but they returned immediately on restart of the engine. I'm going to replace the thermostat but i didn't understand the #U0401 code, so did further research. I found 2017 Bulletin #17-NA-158 which seamed relevent to my issues, and Vehicle Fitment that confirmed my 2019 Chevy Blazer is included. I then came to find that the un-shielded low voltage wires for the coolant temperature sensor are routed through the same harness as high voltage coil wiring. Some of us know that EMI will affect low voltage signals. As an HVAC system designer, I know that un-shielded low voltage communication wiring cannot run parallel two line voltage power wiring. The effects are not continuous, but definitely reoccurring. I also understand there has not been a recall for this issue which surprises me. I can replace the thermostat even in its difficult position, but I don't feel comfortable in separating the low voltage wiring from the harness. I understand that dealers who are aware of this issue, charge a hefty fee to do so. It's definitely one that I can't afford.