Makes / Mercedes-Benz / EQB 300 4MATIC
Mercedes-Benz Repair • Phoenix, AZ
Mercedes-Benz EQB 300 4MATIC Repair in Phoenix, AZ
Common problems, safety recalls and expert service for the Mercedes-Benz EQB 300 4MATIC (2022, 2025).
Own a Mercedes-Benz EQB 300 4MATIC in the Phoenix area? EZ Swap LLC repairs and maintains the Mercedes-Benz EQB 300 4MATIC for model years 2022, 2025. Our shop at 9050 N 9th St handles everything from routine service to diagnostics and major repairs.
To help EQB 300 4MATIC owners know what to watch for, we reviewed public records from the National Highway Traffic Safety Administration (NHTSA). For these model years NHTSA has 13 owner complaints on file for the EQB 300 4MATIC and 5 safety recall campaigns. The most-reported problem areas are electrical system (12), fuel/propulsion system (4), power train (1).
Most-Reported Mercedes-Benz EQB 300 4MATIC Problems
These problem areas come up most often in NHTSA owner complaints for the EQB 300 4MATIC (all model years combined). Complaint counts reflect reports filed, not the share of vehicles affected, so popular and older models naturally have more.
| Problem area (NHTSA component) | Complaints | Share | |
|---|---|---|---|
| Electrical System | 12 | 92% | |
| Fuel/Propulsion System | 4 | 30% | |
| Power Train | 1 | 7% | |
| Engine | 1 | 7% | |
| Vehicle Speed Control | 1 | 7% |
Electrical System
12 of the 13 complaints (92%) mention the electrical system. Electrical problems are made worse by desert heat, which ages batteries, cables and connectors. We test the battery, starter and charging system and trace faults to the actual part. See our battery replacement and starter & alternator repair pages.
Fuel/Propulsion System
4 of the 13 complaints (30%) mention the fuel system. Fuel system problems can cause stalling, hard starts and poor mileage. We test fuel delivery and related sensors to find the real cause. See our no-start diagnostics and check engine light diagnostics pages.
Power Train
1 of the 13 complaints (7%) mention the powertrain. Powertrain complaints can range from rough shifting to loss of drive. We road test, scan for stored codes and inspect fluids before recommending any repair. See our auto repair page.
Mercedes-Benz EQB 300 4MATIC Complaints by Model Year
The EQB 300 4MATIC model years with the most NHTSA complaints on file are 2022, 2025. Older model years have had more time to collect reports, so use this table as a guide for what to inspect, not as a verdict on any one vehicle.
| Model year | Complaints on file | |
|---|---|---|
| 2022 | 11 | |
| 2025 | 2 |
Mercedes-Benz EQB 300 4MATIC Check Engine Codes
NHTSA owner complaints rarely cite specific trouble codes for the EQB 300 4MATIC, so we do not have a model-specific ranking to show. These are the check engine codes we see most often on vehicles in Phoenix heat, and any of them can show up on a Mercedes-Benz.
| Code | What it means |
|---|---|
| P0420 | Catalyst efficiency below threshold (bank 1) Often a worn catalytic converter, but failing oxygen sensors or exhaust leaks can set it too. Can cause an emissions test failure. |
| P0300 | Random or multiple cylinder misfire Worn spark plugs, failing ignition coils, fuel or vacuum problems. Do not ignore a flashing check engine light. |
| P0171 | System too lean (bank 1) Often a vacuum leak, dirty MAF sensor, weak fuel delivery or a failing oxygen sensor. |
| P0455 | EVAP system large leak Missing or loose gas cap, or a disconnected or cracked vapor hose. |
| P0128 | Coolant temperature below thermostat regulating temperature Usually a thermostat stuck open. Fix it to restore efficiency and cabin heat. |
| P0442 | EVAP system small leak Loose or worn gas cap, cracked hose or purge or vent valve. |
| P0301 | Cylinder 1 misfire Commonly a bad spark plug or ignition coil on that cylinder. |
| P0401 | EGR flow insufficient Clogged EGR passages or a stuck EGR valve. |
Got a check engine light on your EQB 300 4MATIC? A code is a clue, not a diagnosis, so we scan it and test the system before replacing anything. See our check engine light diagnostics.
Mercedes-Benz EQB 300 4MATIC Safety Recalls
NHTSA lists 5 recall campaigns for the EQB 300 4MATIC in these model years, most often involving electrical system, power train. Recalls are repaired by the manufacturer at no charge to you, but each applies only to certain vehicles. Look up your VIN at nhtsa.gov/recalls.
- 2026 recall, Electrical System (campaign 26V073000): Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2023-2024 EQB 250+, 2022-2024 EQB 300 4MATIC, and EQB 350 4MATIC vehicles. The high voltage battery may fail internally and lead to a vehicle fire while parked or driving.
- 2025 recall, Electrical System (campaign 25V050000): Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2022-2025 EQB 250, EQB 300 4MATIC, and EQB 350 4MATIC electric vehicles. The high voltage battery may fail internally and lead to a vehicle fire while parked or driving.
- 2025 recall, Electrical System (campaign 25V487000): Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2022-2023 EQB 350 4MATIC, and EQB 300 4MATIC vehicles.
- 2025 recall, Electrical System (campaign 25V894000): Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2023 EQB 250, 2022-2023 EQB 300 4MATIC, and EQB 350 4MATIC vehicles. The high voltage battery may fail internally and lead to a vehicle fire while parked or driving.
- 2024 recall, Power Train (campaign 24V331000): Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2022 EQB 300 and EQB 350 vehicles. The welded spur gear within the front axle electric drivetrain may not have been welded properly.
Keeping a Mercedes-Benz EQB 300 4MATIC Reliable in Phoenix
Arizona heat is the hardest test a Mercedes-Benz will face. Batteries, belts, hoses, tires and engine oil all wear faster here, and a EQB 300 4MATIC that spends its life in stop-and-go Valley traffic needs maintenance earlier than the owner's manual's normal schedule suggests.
Our recommendation for EQB 300 4MATIC owners: follow the severe-service schedule, test the battery before every summer, inspect brakes and tires twice a year, and have any warning light diagnosed instead of ignored. If you are shopping for a used Mercedes-Benz EQB 300 4MATIC, a pre-purchase inspection shows what the paperwork does not.
Mercedes-Benz EQB 300 4MATIC Services at EZ Swap LLC
Get the details on our Phoenix Mercedes-Benz EQB 300 4MATIC repair service, or choose a service below.
Battery Replacement
Test, replace and protect against Phoenix heat.
Details →Starter & Alternator Repair
Charging and starting system repair.
Details →No-Start Diagnostics
Find out why it will not start.
Details →Check Engine Light Diagnostics
Scan, test and pinpoint the real cause.
Details →Auto Repair
All makes and models, from domestic trucks to imports.
Details →Oil Change & Maintenance
Oil, filters, fluids, tires and scheduled service.
Details →Mercedes-Benz EQB 300 4MATIC FAQ
What are the most common problems with the Mercedes-Benz EQB 300 4MATIC?
Based on NHTSA owner complaints, the most-reported problem areas for the Mercedes-Benz EQB 300 4MATIC are electrical system (12), fuel/propulsion system (4), power train (1). Complaint counts reflect reports filed, not the share of vehicles affected.
Which EQB 300 4MATIC model years have the most complaints?
The EQB 300 4MATIC model years with the most NHTSA complaints on file are 2022, 2025. Older years have had longer to collect reports, so inspect any specific vehicle before buying.
What check engine codes are common on the Mercedes-Benz EQB 300 4MATIC?
NHTSA complaints rarely cite specific codes for the Mercedes-Benz EQB 300 4MATIC. On Phoenix vehicles in general, we see P0420, P0300 misfires, P0171 lean conditions and EVAP leaks such as P0455 and P0442 most often. Bring yours in and we will scan and test it.
Does the Mercedes-Benz EQB 300 4MATIC have any safety recalls?
NHTSA lists 5 recall campaigns for the Mercedes-Benz EQB 300 4MATIC across model years 2022, 2025. Each recall applies only to certain vehicles, so enter your VIN at nhtsa.gov/recalls to see if yours is affected.
Do you repair the Mercedes-Benz EQB 300 4MATIC in Phoenix?
Yes. EZ Swap LLC repairs and maintains Mercedes-Benz vehicles including the EQB 300 4MATIC, at 9050 N 9th St in Phoenix. Call or text (602) 246-9063 for an appointment.
Is a pre-purchase inspection worth it for a used Mercedes-Benz EQB 300 4MATIC?
Yes. An inspection checks the engine, transmission, brakes, suspension, A/C and electrical system, and scans for stored codes, so you know the real condition before you buy.
How often should I service my Mercedes-Benz EQB 300 4MATIC in Phoenix?
Follow the severe-service schedule in your owner's manual, since heat and stop-and-go driving count as severe use. Test the battery before summer and inspect brakes and tires regularly.
More Mercedes-Benz Models We Service
Source: public complaint and recall records from the National Highway Traffic Safety Administration (nhtsa.gov). Counts reflect reports filed and do not predict the condition of any individual vehicle.