FAQ – Fixes

ForTwo (450)/Roadster (452)

Q: I have 3 lines on the dash, how did this happen and how do I fix it?

A: This can happen for a variety of reasons, the main one we’ve encountered is a flat battery on your smart car. Other causes include gearbox fault, failing actuator and wiring/earth faults and electrical spikes causing a loss of memory on the SAM (Water Ingress on Smart Roadsters)

On later 450’s and the 451 we’ve found that sometimes simply selecting neutral without the engine running and hold your foot on the break will re-organise the gearbox. Sadly this doesn’t work on all models and seems to be SAM unit dependant.

Depending on the situation, if an issue was present before this fault it may require the underlying fault to be rectified such as a replacement actuator or wiring diagnosis however we can diagnose this for you using the latest software, see HERE. If this issue has suddenly just happened without warning your gearbox may simply need reteaching and this can be done with a Mercedes Benz DAS/Star Systems like the one we use. See our Smart Car Diagnostic Page for prices and services.


Q: The key symbol is flashing on my dash and the indicators flash 9 times when I try to open the car. I’m stuck!

A: Unfortunately you’ve got the most common problem with a Smart Car we know and happens at one stage or another!

Your key fob which holds the information for the immobiliser has gone out of sync with the car. This can happen randomly (although Smart won’t admit that) or because it’s been out of range and pressed several times while in your pocket or bag either way if it won’t unlock the car, it won’t start it either way.

Sometimes the indicators will flash but the car will still start and run, if this is the case replace the battery in the key fob as soon as possible!

If that isn’t the case and the car won’t start as the key symbol is showing, you’ll need your key re-syncing to get up and running again unless you have a spare key for the car.

The key can be re-synced with the car quickly using the Mercedes DAS system. Usually what’s required is the car, the key and a TAN code from Germany however our DAS system has the codes already and saves the extra spend and time required and we can have you running with 5 minutes of arriving.  See our Key Re-syncing Services


Q: I’ve lost of my key completely or it’s been damaged! What can I do?

A: If your key is damaged we can program a new key in and either swap your blade from the old one to the new key or you can have it programmed and taken to any local key cutting service to have the blade copied. However if you’ve lost your key completely, don’t worry….give Mercedes a call and they can order a replacement blade for your Smart which can then be put into our keys. These are around £20 from Mercedes and will require the V5 Logbook. We will come with a new fob and program it in, for prices see New Keys

Discounts for a key re-sync and spare can be negotiated if you contact us.


Q: I’ve got the ABS/ESP Warning Light on the dash. What’s caused it?

A: The most common cause of this issue is faulty reluctor rings (Also known as ABS rings) which help the car measure how fast the car is going and if the wheels are slipping. If the rings are worn or rusty and broken the ECU cannot work the ABS as it should and causes the warning light. To replace them is a fairly easy task and can be seen HERE

If you want to know which ring is broken or to check that it’s the rings, give us a call and we’ll diagnose the car to tell you which one is broken!