2022 MERCEDES-BENZ EQB

Symptoms: Sudden loss of power or complete drivetrain shutdown, Error messages: 'Electric drive system malfunction - visit workshop', Vehicle enters limp mode or refuses to drive, Audible clicking or buzzing from motor compartment before failure

Fix: Inverter replacement requires high-voltage system lockout/tagout, coolant drain, and removal of motor assembly shields. Mercedes TSB covers some under warranty extension but post-warranty units run 8-12 labor hours for R&R and programming. Dual-motor AWD models (300/350) can fail one inverter and still limp on the other.

Estimated cost: $4,500-7,200

Typical onset: 20,000-50,000 mi

Symptoms: Reduced charging speed or charging stops at 80% unexpectedly, Battery overheat warnings in moderate weather, Coolant level low warning with no visible leaks, Range loss of 15-25% beyond normal degradation

Fix: Usually traced to failed coolant pump (electric, dedicated to battery pack) or clogged heat exchanger. Pump replacement is 4-6 hours; full thermal system flush and refill with Mercedes HV coolant adds another 2 hours. Some cases require individual battery module replacement if thermal runaway damaged cells—that's a 12-16 hour job requiring pack disassembly.

Estimated cost: $1,800-3,500

Typical onset: 40,000-70,000 mi

Symptoms: Clunking or thudding when accelerating from stop, Vibration at highway speeds that wasn't there before, Gear position sensor errors or stuck in Park, Fluid seepage around transmission bell housing

Fix: The EQB uses a wet single-speed gearbox with park pawl solenoids and hydraulic mounts. Mounts fail from torque cycling; solenoids stick from moisture intrusion. Mount replacement is 3-4 hours; solenoid pack replacement requires partial gearbox disassembly, 5-7 hours. If internal clutch packs (yes, there's a disconnect clutch) are scored, you're looking at full rebuild or replacement at 14-18 hours.

Estimated cost: $2,200-6,800

Typical onset: 30,000-60,000 mi

Symptoms: Oil spots under front of vehicle after parking, Whining or humming from front axle during turns, Low differential fluid warning (if equipped with sensor), Burning oil smell after spirited driving

Fix: The 300 and 350 4MATIC use a traditional front differential with gear oil. Axle seals fail early—likely due to insufficient break-in procedure or seal material spec. Seal replacement is 2-3 hours per side if caught early. If run low, bearing damage requires full differential rebuild at 8-10 hours plus core exchange.

Estimated cost: $600-1,200

Symptoms: AC blows warm within 6-12 months of purchase, Musty smell from vents that doesn't clear with cabin filter change, Refrigerant recharge lasts only 2-4 weeks, Moisture or condensation inside cabin footwells

Fix: Evaporator core develops pinhole leaks—same issue plaguing other Mercedes models from this era. Replacement requires full dashboard removal: 12-16 hours labor. Must evacuate and recharge R-1234yf refrigerant system (expensive refrigerant). Some TSBs exist but often denied after 3yr/36k mi.

Estimated cost: $3,200-5,500

Typical onset: 50,000-80,000 mi

Symptoms: Clunking over bumps from front or rear suspension, Steering wander or vague on-center feel, Uneven tire wear on inside edges, Visible rust or corrosion on subframe mounting points

Fix: Battery weight (4,000+ lbs total vehicle) accelerates subframe bushing collapse. Rear subframe bushings fail first; front follows. Replacement requires subframe drop, 6-8 hours. If bolts are corroded (salt-belt cars), extraction and frame repair adds 3-5 hours. Alignment mandatory after.

Estimated cost: $1,800-3,200