What is the 2018-2022 Honda Accord 1.5L Turbo Engine Oil Dilution?

The 1.5-liter turbo direct injection engine suffers from an oil dilution defect where unburned fuel enters the engine oil. This occurs when fuel is sprayed into the cylinder, drips down the cylinder walls past the piston rings, and accumulates in the oil pan. The problem is more… Repairs typically run $100-$8,000. Severity: high.

What is the 2018-2022 Honda Accord Automatic Emergency Braking False Activation (CMBS)?

The Collision Mitigation Braking System (CMBS), part of Honda Sensing, may activate randomly without warning even when no obstacle is present. NHTSA investigated over 278 complaints with 107 specifically for Accord models. The investigation covers nearly 3 million vehicles and ha… Repairs typically run $0-$1,500. Severity: high.

What is the 2018-2025 Honda Accord Hybrid Inverter/Power Control Unit (PCU) Cooling System Failure?

The 10th and 11th generation Accord Hybrid uses a dedicated liquid-cooled Power Control Unit (PCU/inverter) that manages power flow between the gas engine, electric motors, and high-voltage battery. The PCU cooling system uses a separate small coolant reservoir (distinct from eng… Repairs typically run $100-$6,000. Severity: high.

What is the 2018-2022 Honda Accord 1.5L Turbo Coolant Intrusion into Cylinders / Head Gasket Coolant-Slot Defect?

On the 1.5L turbo, the sealing surface between cylinders 2 and 3 narrows to a thin sliver of multi-layer-steel head gasket sitting over a coolant slot. Over time coolant can seep into the cylinder head grooves, degrade the head gasket, and leak into a combustion chamber - causing… Repairs typically run $1,500-$3,500. Severity: high.

What is the 2018-2022 Honda Accord A/C Condenser Leak and Refrigerant Loss?

The 10th generation Accord (2018-2022) AC condenser develops pinhole leaks and hairline cracks at the aluminum fin-to-tube brazed joints, causing slow refrigerant loss. The condenser is located at the front of the vehicle behind the grille, where road debris (pebbles, sand, grave… Repairs typically run $600-$1,200. Severity: medium.

What is the 2009-2022 Honda Accord Power Door Lock Actuator Failure - Buzzing and Auto-Cycling Locks?

The plastic gears inside a door-lock actuator wear or strip, causing a loud buzzing/grinding/clicking from inside the door when locking or unlocking, a door that won't lock or unlock with the remote, or — most annoyingly — the auto-locks endlessly cycling (clicking) in stop-and-g… Repairs typically run $100-$450. Severity: low.

Honda · Known Issues

2021 Honda Accord Problems: 8 Known Issues

2021 model year · 9,211+ owner reports · Updated August 2026

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According to Au7o's analysis of 9,211+ owner reports, the 2021 Honda Accord has 8 documented known issues, with 6 rated critical. The most serious are Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374 ($0-$0 repair), ZF 9-Speed Transmission Rough Shifting, Shudder, and Hesitation (2.0T) ($0-$7,000 repair), 1.5L Turbo Engine Oil Dilution ($100-$8,000 repair), Automatic Emergency Braking False Activation (CMBS) ($0-$1,500 repair), Hybrid Inverter/Power Control Unit (PCU) Cooling System Failure ($100-$6,000 repair) and 1.5L Turbo Coolant Intrusion into Cylinders / Head Gasket Coolant-Slot Defect ($1,500-$3,500 repair). The most commonly reported issue is Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374 with 4,231 owner reports. Across all issues with published estimates, repair costs range from $100 to $8,000. DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common Honda Accord problems?

According to Au7o's analysis of 9,211+ owner reports, the 2021 Honda Accord has 8 documented issues. The most frequently reported are: Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374, ZF 9-Speed Transmission Rough Shifting, Shudder, and Hesitation (2.0T), 1.5L Turbo Engine Oil Dilution. Of these, 6 are rated critical and should be addressed promptly.

Is the Honda Accord reliable?

The 2021 Honda Accord has 8 known issues documented across 9,211+ owner reports. 6 issues are rated critical: Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374 and ZF 9-Speed Transmission Rough Shifting, Shudder, and Hesitation (2.0T) and 1.5L Turbo Engine Oil Dilution and Automatic Emergency Braking False Activation (CMBS) and Hybrid Inverter/Power Control Unit (PCU) Cooling System Failure and 1.5L Turbo Coolant Intrusion into Cylinders / Head Gasket Coolant-Slot Defect. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Honda Accord problems?

Repair costs for known Honda Accord issues range from $0 to $8,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374, typically costs $0-$0 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2018-2021 Honda Accord Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374?

The 10th generation Accord (2018-2021) is affected by the largest Honda fuel pump recall in history, covering over 5.7 million vehicles. Denso fuel pump impellers were manufactured with improperly molded low-density material. The impellers deform over time under fuel exposure, ex… Repairs typically run $0-$0. Severity: high.

All 8 Known Issues

Other Honda Models

Frequently Asked Questions

What are the most common Honda Accord problems?

Is the Honda Accord reliable?

How much does it cost to fix common Honda Accord problems?

What is the 2018-2021 Honda Accord Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374?

What is the 2018-2022 Honda Accord ZF 9-Speed Transmission Rough Shifting, Shudder, and Hesitation (2.0T)?

2018-2025 Honda Accord: Hybrid Inverter/Power Control Unit (PCU) Cooling System Failure#

2009-2022 Honda Accord: Power Door Lock Actuator Failure - Buzzing and Auto-Cycling Locks#

2018-2022 Honda Accord: 1.5L Turbo Coolant Intrusion into Cylinders / Head Gasket Coolant-Slot Defect#

2018-2022 Honda Accord: A/C Condenser Leak and Refrigerant Loss#

2018-2021 Honda Accord: Denso Fuel Pump Impeller Failure - Safety Recall NHTSA 20V-374#

2018-2022 Honda Accord: ZF 9-Speed Transmission Rough Shifting, Shudder, and Hesitation (2.0T)#

2018-2022 Honda Accord: 1.5L Turbo Engine Oil Dilution#

2018-2022 Honda Accord: Automatic Emergency Braking False Activation (CMBS)#