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What Could Cause the Smart Instrument Cluster to Show Three Lines

Model: Smart Smart 451 - Years: 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015
Part: Instrument cluster

Video tutorial

When the instrument cluster of the Smart shows three lines, it indicates that there are issues with the gearbox and it cannot engage; otherwise, an "N" would appear. To diagnose the problem, you need to obtain an OBDII reader, which can easily be found on any e-commerce platform for a few pounds.

The most common cause of failure is damaged wiring from the controller to the gearbox engine connector. These wires may touch the intercooler housing, leading to abrasions, possibly a frayed wire.

The video also shows wires touching each other, which can create issues; there may be a damaged sensor, or the problem could be with the gearbox motor. Often, it is the moisture that damages the wiring.


Updated on 11 July 2026 by ScegliAuto


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