Steering Wheel Removal
The steering wheel is a delicate item, I will not take any responsibility if you damage your steering wheel. If you are unsure about proceeding then seek a Smart specialist, most of us are friendly.
Reasons to remove are upgrading to paddle shift, replacing the airbag, cleaning the contacts if you have paddle issues.
The rear of the steering wheel is fitted with a steering angle sensor. This is a disc that rotates whilst you steer to let the ESP know what way you're turning. It is easily damaged as I will mention throughout this guide.
Tools needed: T40 Torx screw driver & 10mm socket with ratchet
Removing the battery is not essential when removing the steering wheel, I have removed hundreds without disconnecting the battery. The most important thing not to do if you are leaving the battery connected is turn the ignition on. If you do you will see the airbag light on the speedo light up and this will need cleared using a diagnostic tool.
If you do wish to remove the battery to ensure the light doesn't come on if you accidentally turn the ignition on then pop out the front boot bin, undo the 10mm nut on the live wire and lift the cable up so it's resting on the steering rack like below so it can't make contact.
For the purpose of this guide I am going to explain fitting a paddle shift wheel to a car with the standard two spoke wheel.
First thing you want to do when sitting in the car is locate the hole in the bottom of the steering wheel where the T40 fitting bolt is located.
I have turned the wheel 90 degrees in the picture below to show the hole where the bolt is. When removing the steering wheel we will remove it with the wheels perfectly straight at all times when removing & fitting, not at 90, 180 or 270 degrees.
Stick your T40 screw driver up the hole and in to the T40 bolt.
Turn the screw clockwise until you hear it clicking. The bolt does not come out, it remains located inside.
DO NOT TURN THE STEERING WHEEL WHEN REMOVING THIS BOLT.
THE BOLT GOES THROUGH THE ANGLE SENSOR, IF YOU TURN THE WHEEL YOU WILL SNAP THE ANGLE SENSOR AND IT IS NOT AVAILABLE TO PURCHASE SEPARATELY.
With the bolt fully unscrewed grab both sides (I could only grab one side as I had the camera in my right hand) and wiggle it towards you.
Unclip the two plugs that go in to the angle sensor.
It is still important not to turn the angle sensor.
The wheel you have bought should have been removed straight. Only follow the below steps if you think it is not straight and are confident to do so.
To check it is straight screw the T40 bolt fully in and remove the screw driver.
The angle sensor can now be spun freely, rotate it 2 turns to the left and back again and then two turns to the right and back again. This is the central point for the angle sensor. If at any point when turning you get resistance turn it the opposite way twice. If you feel resistance you are the end of the angle sensors ribbon tension point and if you keep turning it will snap.
Once you are sure it is straight unscrew the T40 bolt again until it clicks.
The paddle shift uses the same two plugs as the standard wheel. Plug these in and slide it up on to the steering column. As seen in the second picture below there are two locating pins.
IT IS STILL IMPORTANT NOT TO TURN THE STEERING WHEEL, REMEMBER THAT T40 BOLT IS STILL OUT.
With the new wheel on, tighten the T40 Bolt anti clockwise fully. If you have the screw driver shown in the picture below it is possible to stick another through the top to ensure it is extra tight.
REMEMBER DO NOT TURN THE STEERING WHEEL UNTIL THAT T40 BOLT IS FULLY TIGHT AND THE SCREW DRIVER IS REMOVED.
There we go, one paddle wheel fitted.
There is a plug that needs swapped above the SAM Unit, I'll add pictures of that soon as I forgot to take one whilst in the footwell.
Paddle shift requires a TAN code to activate the paddles.
Any Smart specialist including myself or Mercedes dealer can carry out TAN coding.