Electrical System Problems of Chevrolet Blazer - part 1

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).

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The contact owns a 2024 Chevrolet Blazer. The contact stated that while driving 20 mph with 100 miles of charge, the vehicle stalled and shut off. The screen was black, unresponsive, and failed to start. The vehicle was towed to the local dealer, where it was diagnosed with a power module failure. The part was on back order. The electric module was previously replaced. The vehicle was not repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was 10,381.

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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.

Once I turn the vehicle off, there is a loud sound coming from the engine area that sounds like a fan. Then the first incident of the fan ongoing after the vehicle was powered off, a battery light was on the internal driver dashboard and stayed on. The battery was recently replaced during 2026 so the battery should not be anywhere near dead, dying, or needing to be checked.

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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.

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.

Driver information centre (dic) and infotainment go dark. This has happened twice now over the last 2 months. While driving suddenly the infotainment goes blank and loses the radio and then the dic follows by going blank (dark). So I was left with no speed indication. The car drives normally during that time. After 30 seconds to a minute the screens come back on as if it rebooted while driving.

2019 chevy Blazer. Car would not turn off the electrical components when parked. Put car in park and walked away and there is a warning note that says, "shift to park. " but the car was in park. Called chevy and they know about the issue on the 2019-2023 vehicles. They sent me the technical service bulletin. Back in 2020, the car had the shifting harness and button replaced and we just had to have it replaced again because it is a consistent issue with the vehicle. Except this time, the dealer charged us $668. 40 to fix it! it is a known issue by the company and they sent me the service bulletin to get it fixed. It should have been covered by chevy, or, at least a recall should be instituted. The power to the car wouldn't shut off. We were able to jump the car to get it started again.

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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!!.

The vehicle has turned off twice while driving. Endangering the safety of everyone in the vehicle.

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

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.

On two separate occasions the vehicle lost all power while driving. On December 5, 2025 turning on to a main road from parking lot the vehicle shut off with no prior warning lights. Shifted vehicle to park. No power to anything, unable to unlock doors, unable to turn on hazard flashers, stuck in the middle of the road at night. Waited a minute and pressed the start button and vehicle started with no problem. Again, on February 24 , 2026 making a left turn in intersection, without any warning the vehicle shut off… no power at all. Stuck in middle of road with no lights , no hazard flashers ,unable to get out of the car. Few minutes later vehicle started again. The vehicle did not stall while stopped, it completely lost power while moving. Reported problem to west herr Chevrolet of hamburg NY , brought vehicle in to dealership on February 25, 2026 and they were “unable to duplicate the concerns” the dealership paperwork states that the vehicle stalled while stopped, this vehicle lost all power while it was moving. We now have the vehicle back in our possession but are extremely concerned for our safety and the safety of others.

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This vehicle experiences multiple recurring safety-critical system failures while driving, creating a dangerous operating condition for both the driver and the public. 1. Dashboard / instrument cluster failure while driving while the vehicle is in motion, the dashboard display intermittently shuts off completely. When this occurs, I cannot see my speed, warning lights, battery status, or any other gauges. This creates a severe safety risk because I am effectively driving without any instrument information. The issue occurs while actively operating the vehicle on public roads. 2. Navigation / gps location failure the vehicle’s built-in mapping system frequently shows my location several states away from my actual position. Even though the location is incorrect, the system continues to provide turn-by-turn navigation instructions based on the incorrect location. If these directions were followed, it could cause a driver to make unsafe maneuvers or become distracted while attempting to correct the navigation error. 3. False automatic emergency braking activation the automatic braking system frequently activates even when there are no vehicles, pedestrians, or obstacles present. The vehicle abruptly slows or brakes on open roads with nothing nearby. This creates a significant safety hazard because it could cause a rear-end collision if another vehicle is following. Repair history / ongoing issue: this vehicle has been taken in for repair multiple times for these issues. Despite attempted repairs, the problems continue to occur. The recurring nature of these failures indicates a systemic defect that has not been corrected. Safety concern: these failures create multiple hazardous driving conditions: loss of dashboard information while driving incorrect navigation location and directions unintended automatic braking events allowing this vehicle to remain in service with these unresolved defects places both the driver and the public at risk. Request: I am requesti.

Shift to park issue: known issue where the car fails to recognize it is in park, preventing it from shutting off. Electronics: potential blanked-out display screens, usb port issues, and malfunctioning cameras. Steering assist: restricted, temperature gauge goes to cold and radiator fan blows hard. I have to unplug negative cable to battery and reconnect and everything goes back to normal.

On February 4, 2026, my wife drove to the bank, a trip of about 10 to 15 minutes, and turned off the car at the atm. When she tried to leave, the vehicle wouldn't start. After a while, she opened and closed the door and locked and unlocked the car twice with the remote control, and the vehicle started and she was able to drive, but all the warning lights on the dashboard remained on. It is currently at a Chevrolet dealership for diagnosis.

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?.

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.

Chevy of wasilla, ak did not properly inspect a safety recall for the rear parking brake harness. After I showed the dealership the pictures of the holes in the brake harness, I was told that the holes in the brake harness is a feature to let water out. Pictures are attached of said holes in brake harness and text message with dealership representative.

Around 55,000 miles, my 2021 Chevrolet Blazer experienced a throttle body failure. The check engine light illuminated and the vehicle entered a reduced power/limp mode condition. Throttle response was significantly limited, and the vehicle could not accelerate normally. While the vehicle remained drivable, it took substantially longer to reach speed, which could pose a safety risk when merging into traffic or crossing intersections. Diagnostic trouble code p2101 (throttle actuator position performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. This component is a critical engine control system, and failure could affect acceleration and vehicle control, posing a potential safety risk. The failure occurred well before expected service life and required a costly repair. The component has been replaced and is available for inspection upon request. I believe this may represent a premature defect and should be investigated for similar failures in other vehicles. ?.

This submission is an additional report related to NHTSA complaint #11714381. At approximately 55,000 miles, my 2021 Chevrolet Blazer experienced a sudden throttle body failure while driving. The vehicle entered reduced engine power/limp mode without warning and acceleration was significantly limited. This created a safety concern while driving in traffic, particularly when merging and crossing intersections. Diagnostic code p2101 (throttle actuator position performance) was present. A Chevrolet dealer confirmed an internal throttle body failure and replaced the throttle body assembly. Although the repair was completed, this failure occurred at relatively low mileage for a critical engine control component. A sudden loss of acceleration can pose a safety risk depending on traffic conditions. Since filing my original complaint, I have identified multiple similar reports online and in owner forums describing premature throttle body failures in gm vehicles with similar symptoms (reduced power/limp mode and limited acceleration). This suggests the possibility of a broader pattern involving this component. I am submitting this additional report so that NHTSA has a complete record of the incident and potential pattern of premature throttle body failures. If this issue is widespread, it may warrant further review or investigation as it affects vehicle acceleration and safe operation.

I have found multiple times that the instrument panel (ipc) display and the center infotainment displays have gone dark while driving. This has put me in unsafe driving situations because I am unable to monitor my speed and other important information displayed on the dashboard, or to control critical safety controls such as headlights, and other adas safety controls. Several software updates have been installed by the dealership, but the problem has persisted, suggesting a hardware issue with the radio unit. The manufacture insist it is a software problem and that they are working on a solution. Declining to replace the radio under warranty, additionally, they want me to wait until a new update is released, and in the meantime, my bumper-to-bumper warranty is about to expire. I have found that the radio unit is the main control module for both displays, multiple adas controls, and headlights, and it should be recalled, with the manufacturer extending the warranty or including the radio as a safety feature under the extended powertrain warranty.

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.

Telecommunications module failed - no onstar, no navigation which means no help to find charging station, and mychevrolet app remote connection is not functional. Local dealer states this is a known issue but there is a significant backlog to investigate, and no loaner vehicles available. Wide spread issue across many gm vehicles. Very disappointing experience including service repair. Due to lack of loaner I am unable to drop off as this is my primary driven vehicle.

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.

The contact owns a 2024 Chevrolet Blazer. The contact stated that while driving 30 mph on an icy road, the vehicle swerved out of the intended lane because of an ice patch on the road. The contact lost control of the vehicle, and the vehicle continued to swerve, almost causing a crash. There was no warning light illuminated. The vehicle was taken to a dealer, where the contact was informed that the vehicle needed a 4-wheel alignment. The manufacturer was notified of the failure, and the contact was informed that there were no recalls on the VIN related to the failure. The contact was then referred to the NHTSA hotline to file a complaint. The vehicle was repaired. The failure mileage was approximately 22,000.

My car lost power twice in the middle of heavy traffic we could have gotten killed . I was told it was a battery I bought a battery it happened again . The car goes totally black and it locks you in the vehicle you can’t get out I had to call for help scared to death.

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.

Charging hatch door will not open. First noticed the problem when it got very cold here. <-15f did not try to pry door open. Hatch needs to be reliable iin all weather. Happened December 13, 2025.

"steering assist reduced" message was displayed. At the same time the temperature gauge stopped working and after I shut the car off, the motor fan ran full force for 10+ minutes. Shows no check engine light.

The shift-to-park sensor in my 2019 chevy Blazer rs is malfunctioning. After shifting into park, the vehicle does not detect that it is in park and displays a “shift to park” message. The issue is/has been ongoing and now it is almost impossible to bypass with wiggling the shifter. 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 was taken in to the dealership in November/December 2025 due to multiple warning lights: “shift to park”, "steering assist", "stabilink" and the usb-c charging port under the radio screen will stop working all together when this happens as well. This started around September 2025 and has occurred regularly since.

Telematics control module failure.

Car was running fine yesterday, today does not want to start. Thought it was the battery, bought anew battery. Still wouldn't start. Rest of cat is getting great power. Code reader is reading its a fuel pump control moduler which just so happens to be in an open recall for my exact year of vehicle yet my VIN number does not pop up on the GMC website under active recall. I have a 2021 chevy Blazer .

Car is displaying a “steering assist is reduced drive with caution” engine light is on and fan continues to run for 5-8 minutes after car is turned off. Was told by a mechanic it is a p0128 code, coolant thermostat. This is the third time it has happened in the last year. Other two times the codes cleared.

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