	Weakness	Cost
✖	Clutch Actuator Defective (3-Bar Fault) The electric clutch actuator (part no. A4512500062) frequently fails from 80,000–100,000 km. The shaft of the internal electric motor breaks, and gears can no longer be selected. Three dashes on the display, limp mode, or vehicle completely undriveable. Symptoms: Three dashes/bars on display instead of gear readout, gearbox does not clutch or judders heavily, vehicle in limp mode from 90,000 km Ad A4512500062 A4518290201 Smart 451 clutch actuator Smart 451 shift actuator	Medium
✖	Gearbox Shift Actuator Defective The shift actuator (part no. A4518290201) controls the electronic gear selection. When it fails, individual gears are lost or the gearbox no longer shifts at all. Typical problem on older examples from 100,000 km. Symptoms: Individual gears cannot be engaged, shifting problems, limp mode, error message on display from 100,000 km Ad A4518290201 Smart 451 shift actuator Smart fortwo 451 Gangsteller	Medium

Frequently Asked Questions

What problems and weaknesses does the Smart ForTwo 451 Cabrio have? +

The Smart ForTwo 451 as Cabrio has 27 known weaknesses, 14 vehicle-related.

Which engine is recommended? +

Be Careful: 3B21 (1.0L), Smart-ED (Elektromotor). No engine is rated 'Good Choice'.

Is the Smart ForTwo 451 Cabrio worth buying used? +

Caution is advised with the Smart ForTwo 451 Cabrio — 1 of 3 engine variants are rated 'Stay Away!'.

Last updated: February 2026 · All information without guarantee

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