2020 Chevrolet Blazer electrical problems

ELECTRICAL SYSTEM

The car is not sensing that it is in park when it is. When I place it in park and turn the car off it dings and says shift into park however it already is in park. Therefore the car will not turn off. I had to jiggle the shift or turn the car on, reverse then go forward then park to get it to register. This has taken up to 10 minutes and it’s getting worse. This is a known issue that is referenced in GM Technical Service Bulletin 19-NA-206.

NHTSA complaint #11758760 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The vehicle experiences a constant cooling system failure that appears to be related to the thermostat. Beginning at approximately 40,000 miles, the engine cooling fan started running continuously at high speed whenever the vehicle is operating. At the same time, the air conditioning stopped functioning properly and the vehicle began displaying a warning message indicating that steering assist is unavailable or reduced. The vehicle is available for inspection upon request. This condition creates a safety concern because the steering assist warning indicates a potential reduction or loss of power steering assistance, which could increase steering effort and make the vehicle more difficult to control, particularly during low-speed maneuvers or emergency situations. The warning appears during normal vehicle operation and can distract the driver. The ongoing failure of multiple vehicle systems raises concerns about the safe and reliable operation of the vehicle. The problem has been present continuously since first appearing at approximately 40,000 miles and is fully reproducible. The condition occurs every time the vehicle is driven and has not corrected itself. Symptoms include the engine cooling fan running continuously, loss of air conditioning, and a steering assist warning message. Based on reports from other Chevrolet Blazer owners experiencing similar thermostat-related failures, this may represent a common defect that warrants investigation and consideration for a safety recall.

NHTSA complaint #11745859 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The contact owns a 2020 Chevrolet Blazer. The contact stated that while driving approximately 70 MPH, the message, "Steering Assist Reduced - Drive Carefully” was displayed. The contact stated that the A/C shut off and the windshield defroster failed after the message was displayed. The vehicle was taken to the dealer, and the contact was informed that the repair was not covered. The manufacturer was informed of the failure and confirmed that the vehicle was not included in the “Special Coverage" for the repair. The contact was referred to the NHTSA Hotline to report the failure. The failure mileage was approximately 65,000.

NHTSA complaint #11745865 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The contact owns a 2020 Chevrolet Blazer. The contact stated that the front passenger’s seat belt buckle was inoperable. The contact buckle was jammed and failed to properly secure the seat belt in place. The contact stated that while driving and stopped at a red light, the traffic light turned green and the accelerator pedal was depressed; however, the vehicle surged forward unexpectedly while rolling. Additionally, the contact stated that the infotainment system intermittently displayed a blank or distorted screen, became frozen and was unresponsive to the touch commands. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failures. The approximate failure mileage was 75,000.

NHTSA complaint #11744808 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

This is what came up on my screen.Steering wheel assist reduced.Drive with care. My hot and cold gauge drop to C and stayed there for about 4 days and my a/c was blowing out hot air. I was told a lot of these Suvs have done this.

NHTSA complaint #11741925 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Vehicle: 2020 Chevrolet Blazer Issue: “Shift to Park” malfunction Description: The vehicle repeatedly displays a “Shift to Park” warning message even when the gear selector is fully placed in Park. Because of this issue, the vehicle does not always shut off properly and may continue running electrical systems after the engine is turned off. Symptoms include: * Warning message stating “Shift to Park” * Vehicle not recognizing that it is in Park * Difficulty shutting vehicle off completely * Doors/horn behavior acting abnormally after exiting vehicle * Concern about battery drain and vehicle safety The issue occurs intermittently but has become more frequent over time. The shifter often must be moved multiple times before the warning clears. This appears to be a widespread issue affecting many GM vehicles and may involve a defective shifter assembly or park switch component. I am concerned this defect could: * cause unexpected battery failure, * prevent the vehicle from shutting down properly, * create a safety risk if the vehicle does not correctly recognize Park status

NHTSA complaint #11738429 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I am contacting you regarding my 2020 Chevy Blazer with approx $55,580 Miles. the vehicle is experiencing multiple issues consistent with the know thermostat problem reported on many 2020 Blazer, including the P0128 code, cooling fans running at high speed and "steering Assist Reduced" warnings. The Steering wheel has now become hard to turn while driving, creating a serious safety concern for me and my family, I m [XXX] old and yesterday in mother's day) while I was driving on the expressway with my grandchildren in the vehicle, the steering suddenly became very had to turn and I was almost involved in an accident, This situation was extremely alarming and poses a significant safety risk. PLEASE review many complains from owners who have experienced the same dangerous issue involving the "steering assist Reduce- Drive with Care", warning, sudden stiff steering thermostat malfunction, loss of A/C, and overheating symptoms. I urge Chevrolet and the appropriate safety authorities to investigate this issue and take immediate corrective action to avoid loss of human life. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11737156 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

My car will be running fine but the lights on the AC panel wont work. My car will stop and shut down while driving. Ive taken it in for service and they told me my battery cabels were lose. The second time it happened I got a notification of low battery level and it shut off and will not start. I just replace the battery 2 years ago. The service department tested my battery and said it was fine

NHTSA complaint #11735381 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The temperature gauge on my 2020 Chevrolet Blazer stopped working and remains stuck on “cold” at all times. At the same time, the air conditioning stopped functioning properly and only blows hot air. The vehicle was taken to a repair shop where diagnostics indicated a faulty thermostat sensor. The thermostat sensor was replaced and the issue appeared fixed. However, less than two weeks later, the same problem returned. The temperature gauge again stays on cold permanently, and the AC blows hot air. This appears to be a recurring issue affecting the vehicle’s cooling system and temperature monitoring

NHTSA complaint #11734563 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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.

NHTSA complaint #11733563 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

2020 Chevy Blazer RS 3.6L V6: 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.

NHTSA complaint #11731894 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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!!

NHTSA complaint #11724826 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Vehicle has shift to park light and will not turn off even with the shifter in the park position.

NHTSA complaint #11723443 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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.

NHTSA complaint #11715931 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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?

NHTSA complaint #11715555 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The driver information center suddenly indicated steering assist disabled, temperature gauge drops to below cold, air conditioning blows warm air. This issue has happened several times and is able to be reset by disconnecting/reconnecting the battery or using a scan tool. Temperature sensor is not the cause in my opinion, and I have read that the harness for the temperature sensor also includes the coil wires, which can lead to electrical/rf interference, triggering this issue. I have read about many owners having this same issue, even after temperature sensor and thermostat replacement, at low mileages. This should be recalled and handled by GM, whatever the cause.

NHTSA complaint #11713538 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Action required steering assist reduced and coolant temperature at 0. Air con blowing hot and check engine light on. The vehicle became hard to handle and keep in my lane on the interstate at high speeds. The problem has persisted. It has not been recitfied. I am not driving the car to avoid damage and danger. I bought the blazer on 1/6/26. The lights and issues began 8 days later. Dealership will not help me. 2020 Blazer RS AWD bought from Morgan city Toyota Louisiana

NHTSA complaint #11711479 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Very bad clunnk on driver side when hitting any bump on the road and it's loud.dealer ship sold me the car like that . Electrical issue gauge cluster radio cluster turn signals your first camera anything that works off the instrument cluster of the radio TV screen goes off while I'm driving comes back on hit a bump it comes back on no headlights driving at night time. The dealership sold me the car like this.

NHTSA complaint #11710166 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Car is cutting off while driving , I’m driving on a busy road , engine jerks and stall out leaving me with no power to accelerate. Brakes work but gas pedal not so much . I have to cut off the car hoping it turns on , cause it don’t want to turn over once I decide to turn it off

NHTSA complaint #11708234 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

There seems to be a constant problem with the service driver assist error code popping up and check engine light coming on. The ac heating keeps losing temperature. I've looked for support for this issue and it seems to be a common problem for chevy owners. Why isn't there a recall on this.

NHTSA complaint #11706697 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Thermostat gauge isnt moving along side a message saying "Steering assis is reduced drive with care"

NHTSA complaint #11696724 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I got into my vehicle and it said “steering assist reduced. Drive with care”. the A/C stops working and refuses to cool as well as the cooled seats. The thermostat for the coolant reads “C” despite driving it 40+ miles in 83 degree weather. Tried disconnecting battery upon research and finding out many other people are having the same problem. The light turned off and came right back on the following morning

NHTSA complaint #11696282 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Shift to park issue. Vehicle shifts into park but does not register as such. Therefore, the vehicle keeps running and will not turn off or allow you to exist the vehicle. This is already a know issue with certain GM vehicles as is evident by a recall and Service Bulletins. However, none of those include the 2020 Chevy Blazer.

NHTSA complaint #11695572 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Component/System Involved: The shift-to-park sensor in my 2020 Chevy Blazer is malfunctioning. After shifting into park, the vehicle does not detect it and displays a “Shift to Park” message. The issue is ongoing, and the component is available for inspection if needed. Safety Risk: The vehicle cannot be fully shut off or locked, increasing the risk of battery drain or unintended movement. This poses a safety risk if the vehicle is left in public or on an incline. Inspection History: The vehicle has not been inspected Warning Signs: The “Shift to Park” message appears when trying to turn off the vehicle, despite the gear being in park. This started around Fall 2024 and has occurred regularly since.

NHTSA complaint #11694202 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Component/System Involved: The electric power steering system in my 2020 Chevy Blazer is malfunctioning. A warning appears on the dashboard: “Steering Assist is Reduced – Drive with Care.” When this happens, steering becomes very stiff and difficult. The issue is ongoing, and the component is available for inspection if requested. Safety Risk: This creates a serious safety hazard. The sudden loss of steering assist makes it hard to turn the wheel, especially at low speeds or when maneuvering. It puts me and others at risk, especially if it happens in traffic or while turning. Problem Confirmed by Dealer: No, the issue has not yet been inspected or confirmed by a dealer or service center. Inspection History: The vehicle has not been inspected by a dealership, manufacturer, police, or insurance. Warning Signs: The only warning is the “Steering Assist is Reduced – Drive with Care” message, which appears randomly—sometimes at startup, sometimes while driving. The issue began around 10/15/2024 and continues to be an on going issue.

NHTSA complaint #11694205 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

When I try to park the car, it says shift to park. Sometimes I can’t get the car to go into park to exit the vehicle or other times. I’ve shut the door and it has stayed on with the accessories because it won’t shut off

NHTSA complaint #11693643 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Shift to park message on display when car is already in park, preventing the car from turning off completely draining the battery completely.

NHTSA complaint #11693665 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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.

NHTSA complaint #11693039 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Vehicle thermostat would read cold while operating and the AC was not working. A message would populate in the dash stating "steering assist is reduced drive with care." Multiple forums stated it was a thermostat issue or temperature sensor. Also attempted to disconnect the battery for several minutes which would in turn clear the message and all would be working fine. This has been done multiple times and is at random when the message and AC stop working

NHTSA complaint #11691268 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The original issue was that the temperature gauge was pegged on cold and the A/C was inoperative. The vehicle’s fans would run continuously even when the engine was cold. This created a safety concern since the engine’s actual temperature could not be monitored, and loss of A/C affected drivability in hot conditions. The issue appears related to the engine’s coolant temperature sensor or thermostat system, which causes incorrect signals to the temperature gauge and HVAC system. The condition has been reported by multiple owners of the 2020 Chevy Blazer 3.6L. In my case, the malfunction happened suddenly and has been repeatable. There were no prior warning lamps until the issue occurred, at which point the temperature gauge stopped working properly and the air conditioning failed.

NHTSA complaint #11690677 — an unverified report by a vehicle owner.