How to reboot a Smart Car software system

Editorial clarification: The Computer Weekly Developer Network blog primarily exists to cover enterprise-centric software application development and data management industry news and analysis — we occasionally look at hardware products from a internal software perspective, hence the reason for today’s post.



As we know, we have spent the last couple of decades and more putting more and more electronics into our automobiles.

From an embedded software perspective this should all be good news i.e. more in-car entertainment, electronic central locking, satellite navigation units and system health intelligence… these are all good things.

Well they are, if they work.

But there comes a time when you just kind of wish that your car locks worked by plain old key-and-lock mechanisms, rather than via the ‘point-and-click’ wireless ‘key fob‘ systems that we have all got so used to now.

The story here is simple enough.

A Smart Car’s lock system goes haywire when started on Boxing Day after a trip to from London to Salisbury UK — the ignition key can not be removed from the car without the central locking going into a sort of ‘possessed dance’ with itself, constantly clicking on and off.

Your driver (that’s me) has the foresight to a) initially leave the ignition key in the car so that the locks don’t burn out and then b) disconnect one of the battery terminals so that they key can be removed.

A dead car with disconnected battery is not an attractive option for a thief it appears, the car sat like this for two weeks untouched.

So what to do?

Green Flag Breakdown’s superb fleet of (often Polish, thankfully, these guys are great) engineers are always on call and our mechanic suggested that it could be down to a ‘rear lock solenoid burnout’ — he was close and in the right ball park.

The problem was down to what is called the Smart’s ‘Zee control unit’ — and this is basically a piece of embedded software (firmware, if you like) that resides on a small motherboard located under the dash quite near to the fuses.


The Zee unit is accessible via a large port similar to the power input socket on the back on an xBox360 — image credit

Mercedes bends

But here’s the real killer part of this story, I took my car to the main London Smart centre which is Mercedes Brentford — and these guys knew what was wrong.

They presented me with a bill estimate for £960 to fix everything that was wrong with the car including the Zee unit (which was estimated individually at £264 inc VAT plus £156 plus VAT for key recoding — so a total of £420 GBP).

What is gut wrenching is that the fix was so simple, but I was not offered the option for a simple quick reboot.

To Mercedes Brentford credit, they should have charged me for the consultation, but as my car is only worth £1000 and the estimate was £960 for fixing, even they felt bad.

So to the fix

After many web searches and Facebook discussion exchanges (thank you everyone!) it turns out that your best option (if you need to get any automotive software reinstalled) is not just a local garage, but an independent specialist that is not a main dealer.


Our saviour in this car was the Smart Clinic in Harrow.

Has (that’s his name) at the Smart Clinic saw our almost dead car, plugged in a Toshiba ToughBook thing, clamped in an Xbox 360 cable to connect it to our car, set out rebooting the whole automobile – started the engine, problem solved.

Less than half an hour and £80 including VAT.

So the moral of this story is…

… electric locks are more trouble than they are worth, always trust a Polish mechanic, never go to a main dealer if you can find an independent dedicated specialist and ask your friends on social media what to do if you have major mechanical issues with any piece of equipment because community knowledge is all-powerful.

Smart Car? Well, sometimes.

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