general problems of the 2020 Chevrolet Blazer - part 1

The check engine light came on with a warning that said "steering assist reduced drive with care". The temperature gauge went to cold and the air condition quit working.

A/c quit working, "caution power steering assist . . . . Working, temperature gauge reading zero ( far left side of gauge. Pf62f code set. Repair shop says very common. $800 to repair due to removal of plenum and other component including water temp sensor and thermostat while your there. $100+. 63k miles on vehicle.

Just took my car to the chevy dealership today and had them go over the car because I keep getting the message steering assist has been reduced and the fan is constantly running at the highest speed and it also makes it where I can not use the a/c or heat in the car! I don’t know the code off hand but it has something to do with the cam shaft and the thermostat for the antifreeze! from what chevy told me today it is a $9000 job to tear down the left side of the engine because the camshaft carrier gasket is leaking oil! which is probably why that code is popping up. Or from what I was told today it could be from the battery which I believe they were trying to shift blame. Either way this camshaft stuff really needs to be investigated!!.

| issues first appeared recorded on 3/9/2026, while odometer read 49,663 miles. Check engine light was caused by error codes p0128 and p01f0. This causes the following issues: * check engine light to appear on the dashboard. * engine temperature gauges to be unreliable at times or completely non functional at others, as it will constantly read the engine temperature "cold". * air conditioning unit to become unreliable at times or completely non functional at others, and only blow hot air. * radiator fan will be stuck running at max speed despite current engine temperature. * a "reduced steering assist" message will periodically appear on the dashboard. * a "service esc" message will periodically appear on the dashboard. * remote start will becomes non functional. | car was taken to a license Chevrolet dealership and had full thermostat housing and thermostat sensors replaced. Dealership confirmed all replaced parts are working correctly and as intended. After picking up the vehicle from the dealership, and driving car for roughly 30 miles, the check engine light appeared on the dashboard again causing all previous issues to return. | several other chevy Blazer 2020 owners have complained of the same issue online, and in forums such [xxx] . | information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

2020 chevy Blazer rs 3. 6l having intermittent issues with ‘check engine’ light activating and giving code p0128 - indicating “coolant thermostat (coolant temperature below thermostat regulating temperature)”. Symptoms include: - temp gauge drops to reading “c” (cold), - ac blows warm/hot air, - dash displays message, “steering assist is reduced, drive with care”, - radiator (electric) fans run full speed. It seems that the computer is interpreting the engine coolant temperature sensor drop as a ‘stuck open’ thermostat, thus the indicated code. However, at the same time it also appears to assume a bad coolant temp sensor, and failsafes to disable the ac and set the radiator fans to max to avoid potential overheating. The problem with this is that this can occur after driving for some period that the engine is suitably warm, then I can pull off the road, disconnect the battery for a few minutes, and everything goes back to normal operation. A broken thermostat would not behave this way. * this happened in Mar 2025 - after disconnecting the battery about 5-6 times over about a 1wk period the code cleared and we were able to pass inspection. The issue did not reoccur until about the same time this year. It has been recurring periodically since. * after reading numerous postings on this issue, with numerous different vehicles that have this engine and computer, I have no faith that the dealership will provide a solution other than charging me to replace the thermostat, and ending up with the same problem a few weeks later.

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with vvt sensor failure. The sensors were replaced; however, the failure recurred. The vehicle was taken back to the mechanic, where a solenoid was replaced. The vehicle was repaired. The contact was informed that if the failure recurred, there might be an internal engine failure. The dealer was not contacted. The manufacturer was notified of the failure and referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 70,000.

I received a check engine light which I took to bell tire for diagnosis. Here is there diagnosis comments: the p01f0 code on a 2020 chevy Blazer means the engine coolant temperature is below the normal operating range, often due to a stuck-open thermostat (or both thermostats in models with dual units), a faulty engine coolant temperature (ect) sensor, or low coolant, leading to poor fuel economy and potential wear; fixing it usually involves replacing the thermostat(s) or sensor after checking coolant levels and wiring. After that I took the vehicle to gm dealership. Even though this is a know issue with many vehicles from same year, I was told that my VIN is not part of recall and dealership ended up charging me 600+ to fix the issue. I am reaching out to seek help as I had exact same problem but gm is not covering the repairs because my VIN is not in the recall. How is that possible?.

I bought this car brand new. 0 miles. I’ve had an oil leak fixed once in it. And now it’s leaking oil again. I have to have it put back in the shop and pay out of pocket once again for now fault of mine. The first time it was leaking from the cam shaft. This is ridiculous. I will also be filing a complaint with chevy.

Engine showing po128 code. Steering assist system reduced power. Engine fan constantly running. Engine temp on dash is stuck on the "c" mark, doesn't move. Thermostat and temp sensor replaced, issue continues. This is a very common problem on gm vehicles with the 3. 6l around the 60,000 mile mark. Gm needs to get it figured out.

2020 Blazer, 65,000 miles. Temp stuck on cold, a/c blows warm aor and driving assistance off. The radiator fan runs continuously. Check engine light on.

Thermostat/thermostat sensor and complete water outlet system replacement at only 52,377 miles. The defective part was located under the intake manifold requiring its removal, excessive labor cost for the repair, and potential future engine issues due to exposed/open head gasket for the repair.

"steering assist reduced” warning message appears on dashboard display and temperature gauge stuck on cold on the dashboard display. I understand this such a common issue with the 2019 and 2020 Blazer that general motors has issued technical service bulletins but refuses to repair these vehicles for free. This is unacceptable! issue a mandatory recall therefore gm must perform the repairs for free.

The thermostat failed on a trip locking in 0 temperature reading and steering assist warning. Licensed mechanic repaired on 10/9/25 invoice is available. 67,509 miles. This could risk overheating and destroying the engine and might cause accident. Two other friends have had similar issues, appears to be a safety defect!.

Engine light on, power steering assist, air conditioning stop working diagnostic tool read p0128 coolant thermostat.

Check engine light on, message saying "steering assist reduced drive with care", engine temperature gauge not moving from c, and ac not working. I have taken it in to be fixed 3x, and they have fixed it 2/3 times but the message has come back again. It is a big issue in 2019/2020 Blazers according to my research.

My vehicle lost complete power while I was sitting at red light. The dashboard went completely out and pop back on stating to put the vehicle in park and push the brake to start. After following those instructions the vehicle failed to start and I left disability until onstar notified mpd to assist. While waiting for assistance I was almost hit 3 times. When mpd arrived on the scene they were able to push the vehicle out of traffic. After my vehicle arrived at the shop I was told the power failure was caused by the malfunction of the DC/DC converter output voltage. I see a bulletin was put out but a recall was my made available. I feel this is a major issue due to the vehicle losing power.

P0128 code for thermostat issue. Fans run after shutting car off. Steering assist reduced message. Check engine light. Chevy knows this is a common issue. This needs to be investigated ASAP.

2020 Chevrolet Blazer, 19900 miles, lightly driven the radiator seam is leaking coolant, which appears to be a known issue as there are numerous complaints on various websites and forums. The vehicle is now unreliable due to an overheating risk.

Warning message indicating steering assist system reduced, engine fan running non-stop, ac blowing hot air, temperature gauge not registering/stuck on cold. Faulty engine temperature sensor and thermostat.

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, the steering wheel became inoperable. The contact stated that the steering wheel became difficult to turn with a reduced steering message displayed. The vehicle was taken to the dealer, where it was diagnosed that the thermostat had failed, which caused the steering wheel to fail, and needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 54,000.

The contact owns a 2020 Chevrolet Blazer. The contact stated while driving approximately 45 mph, the instrument cluster went black, and the vehicle stalled. The contact stated that there was no warning light illuminated or an audible chime heard. The contact stated that several attempts were needed to restart the vehicle. The vehicle was restarted, and the message "vehicle in transport mode" was displayed. The contact stated that the failure was intermittent but reoccurred. The contact stated that the vehicle was not taken to a dealer or independent mechanic to be diagnosed or repaired. The manufacturer was informed of the failure and referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 92,000.

The Blazer's check engine light came on and I had it scanned. The code was po128 indicating that the engine coolant temperature is consistently below the thermostat regulating temperature. We are also getting a message on the vehicle that states the steering assist is reduced, drive with care. The car is also blowing hot air when the ac is on, the temperature gauge is staying at the lowest setting and the fans are running full blast. This seems to be a very common problem with the Chevrolet Blazer.

Vehicle gives warning that steering assist is disabled. I should drive carefully. Also cooling fans run on high and temp gauge reads zero. P0128 I'd code given by computer. When code is cleared vehicle returns to normal operation. I read many, many people have this same problem with no clear correction. Many have replaced thermostat, temp sensors, and problem returns. Sounds like defective wiring to me and if it impacts steering should be an oem problem to remedy.

I have an oil leak and now they are saying both of my camshaft housing gaskets are leaking it's going to take weeks to repair cause it's such a major leak.

To whom it may concern, I am writing to formally file a complaint regarding ongoing and persistent issues with my 2020 Chevrolet Blazer. The vehicle has exhibited repeated problems that I believe may indicate a broader safety or mechanical defect, and I am requesting that the NHTSA investigate these concerns further. Since purchasing the vehicle, I have experienced the check engine light turning on and off repeatedly, without consistent resolution. The following issues have occurred over time, all seemingly related to the engine or control systems: engine cooling system failure: the first major issue involved the engine cooling system. This caused the vehicle to overheat and required service. I was concerned about the potential for engine damage or fire risk due to excessive heat. Variable valve timing (vvt) system malfunction: shortly after the cooling system issue, the vehicle began experiencing problems with the variable valve timing system. This not only affected performance and fuel efficiency but also caused the check engine light to illuminate again. Steering control assist sensor warnings: most recently, the steering control assist sensor has started to malfunction, with warnings frequently popping up on the dashboard. This has impacted steering feel and raises serious safety concerns. Despite multiple service appointments and repairs, these problems persist or reappear. This cycle of temporary fixes without a lasting resolution is both frustrating and concerning from a safety standpoint. I am requesting that the NHTSA look into whether these recurring engine and control system issues are part of a known defect or recall-worthy problem affecting the 2020 chevy Blazer. Thank you for your attention to this matter.

Ongoing engine and steering sensor issues – 2020 Chevrolet Blazer I am filing a complaint regarding repeated safety and mechanical issues with my 2020 Chevrolet Blazer. The vehicle’s check engine light frequently turns on and off, and I have been informed by technicians that it is related to the thermostat system. This issue negatively affects the vehicle’s performance and reliability. Additionally, the “steering assist is reduced – drive with care” warning continues to appear while driving, even when weather and road conditions are normal. This error is reportedly due to a steering control assist sensor, and it raises serious concerns about the safety and handling of the vehicle. The alert causes uncertainty and could potentially impact the power steering functionality, creating a hazardous driving situation. These issues have occurred multiple times despite maintenance, and they appear to be part of a broader pattern of defects affecting other owners of this model year. It is unacceptable for a vehicle this new to have persistent problems that affect both engine operation and steering safety. I urge the NHTSA to investigate these recurring issues with the 2020 chevy Blazer’s thermostat system and steering assist sensor to determine whether a recall or manufacturer intervention is warranted. Safety should not be compromised due to what seems to be systemic defects. Thank you for your attention to this matter.

The thermostat has failed, causing hot air to blow into the car. This is a known and common issue with the 2020 Blazer.

Failure of either coolant temperature sensor or thermostat or both. The a/c is disabled, the temperature gauge does not function, and a message appears on the dash display regarding steering assist not working. With all these issues, it’s impossible to feel safe driving any distances, not knowing whether the vehicle will overheat and damage the engine or other components, or if the steering will actually fail. Both parts have been replaced, at the time, may 4, 2025.

The contact owns a 2020 Chevrolet Blazer. The contact stated while driving at approximately 55 mph and driving up an incline in the road, the check engine warning light had illuminated. The contact stated that the vehicle was shuddering. The contact stated that the failure only occurred while driving uphill. The contact had only recently taken the vehicle to a local dealer for the check engine warning light being illuminated. The vehicle was diagnosed, and the dealer determined that the thermostat and the engine control sensor needed to be replaced. The vehicle was repaired. The contact stated that approximately 1,800 miles after the first repair the check engine warning was illuminated again. The vehicle was taken back to the same dealer. The vehicle was diagnosed, and it was determined that the air flow shutters had been damaged and needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure and had referred the contact to the NHTSA hotline to report the failure. The failure mileage was approximately 97,000.

Steering assist reduced drive with care display, air conditioning turned off, stop and start disabled, temperature monitor at cold, fan blows hard why my 2020 model was not covered under the special coverage n252508350 NHTSA id# 11024390.

To whom it may concern, I purchased a new 2020 chevy Blazer from the dealership five years ago. Since then I have had to replace my battery twice, radiator and now the thermostat all of which have been done at the dealership. The car and all receipts of the repairs are available for inspection if requested. This most recent mechanical issue with the thermostat included the following; fans blowing on high, no ac, check engine light, steering assist reduced message, and temp gauge on c. The car was immediately (same day) taken to the dealership for investigation. Upon inspecting the car the mechanic found the thermostat sticking open and indicated that it would need to be replaced as it was unsafe to drive. A total cost of $1400. It seemed odd that my car is only 5 years old with 75k miles and needing to have the thermostat replaced so I started researching this issue further. . Read more...

Engine fan stuck on high, air conditioner does not work, temperature gauge stuck on cold, driving assist warning light on.

Where do I start. Spring of 2024 I believe, less than 55,000 miles, my transmission went out. No warning. I just went out to my vehicle to go to work and when I put it into reverse, my vehicle make a awful noise, jerked forward almost going into my garage door, then wouldn't move. . I put it back in park, tried to put into reverse again and it wouldn't go. It was stuck in park. Had to get it towed to the dealership where they advised me the transmission went out. It was covered under the drivetrain warranty, but the gm warranty doesn't cover rental. It took almost 4 weeks for gm to approve for a new transmission due to parts being on back order to rebuild my transmission. Several months later, I was driving down the road when the esc light and then it said "shift to neutral & press start" and I lost power. I coasted into a parking lot, got it fired up, but had no air conditioning (of course it was summer). Took it to the dealer and they said my radiator and a/c compressor had to be replaced. Luckily my extended warranty covered the $5000 repair. Now 4 months later I got "steering assist reduced, drive with care" with codes. Took to shop and the codes basically was the temp was to low, but the shop couldn't find anything wrong. Cleared the codes and so far so good, but now my esc light pops on once a week again. I don't even have 60,000 miles on my vehicle.

I purchased this vehicle in March, 2025 from a used dealer. When I got it, I noticed the vehicle was leaking oil on my garage floor. I took it back to used dealer who also agreed there is a leak but couldn't detect it. They sent me to chevy dealer. It has been 3 months now and dealer states the transmission has a seal leak. It seems like a similar recall on same year and model, however my vehicle is not listed as a recall. Why isn't there one?.

I have had to replace the radiator 3 times since I've owned this vehicle. I see where there are others with the same issue. Now I have to replace the thermostat my first radiator was replaced at 16k miles. This is a safety issue because my car over heated and broke down on the highway left me stranded.