IsItAGoodCar
Reliability Guide

Common Problems with the
2021 Mercedes-Benz C-Class (W206)

The W206 launched with the M254 engine and 48V mild-hybrid as standard, plus the large Tesla-style central screen. Early cars had software glitches causing screen freezes and 48V system failures that could prevent the car from starting.

What changed for 2021

  • •New generation with M254 engine
  • •48V mild-hybrid standard
  • •Large central touchscreen
  • •MBUX infotainment

Common MOT watch-outs

  • !48V battery or starter-generator failure
  • !Central screen software freezes
  • !Electrical gremlins
2
Known Issues
1
Serious
0
Moderate
1
Minor

The 2021 period has 2 more issues than the Mercedes-Benz C-Class (W206) average across all year periods.

All Known Issues

48V Mild-Hybrid (EQ Boost) Failure

SeriousElectrics & Electronics

The 48V battery or integrated starter generator can fail, leaving the car unable to start.

Most affected: C 200, C 220 d, C 300

Estimated cost: £0 (Warranty) – £2,000Affects: 2021–2024

Typical symptoms

  • •"Battery Malfunction" warning
  • •Engine fails to start
  • •Loss of start-stop function

What to inspect before you buy

  • ✓Check for recall status or software updates regarding the 48V system

Software and Electronic Glitches

MinorElectrics & Electronics

Frequent reports of central screen freezing and minor electrical bugs.

Estimated cost: £0 (Warranty)Affects: 2021–2024

Typical symptoms

  • •Screen lag
  • •Navigation errors
  • •CarPlay/Android Auto disconnection

What to inspect before you buy

  • ✓Confirm latest software updates have been installed

Buying Tips for the 2021 Mercedes-Benz C-Class (W206)

  • ✓Check 48V system warnings
  • ✓Test central screen responsiveness
  • ✓Verify all software updates applied
2022 Mercedes-Benz C-Class (W206)

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Other Mercedes-Benz C-Class (W206) Year Periods

20212022202320242025

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