[DreamCarOwner]

My 451 has the 2 spoke steering wheel. I just bought a used three spoke one with the shift paddles on it. I hope the air bag from the 2 spoke fits the 3 spoke. But anyway I know to disconnect the battery for 10 minutes before trying to remove the old wheel. I know to use a T-40 torx bit to go up through the hole and loosen the screw up to allow the wheel to come off. Now that is where my knowledge stops. Evilution has steering wheel removal for the 450. Couldn't find the info for the 451 on there. I need advice because I've never messed with an airbag in my life. How can I safely proceed to switch the steering wheel over ? Lastly I didn't get any wiring with the wheel. Is there supposed to be a connector for the wires to the paddles? Thanks. Lonnie DCO

 

[jimvw57]

I don't believe you can just add the paddle shifters on a car without them. You will probably have to have it go through MB to have the SAM updated with a new tan code to enable the option.

 

[davidp]

first install the new wheel then go to a dealer to get the paddles activated
remove the big bolt holding the wheel and the rest is easy.. everything is plug n play

 

[jzchen]

store airbag with deployment side up. Do not expose to >100C

steering and turn signal switch must be in the center position
disconnect neg battery cable
remove lower steering column trim
detach clock spring and air bag connector
undo bolt under steering wheel (stays on wheel)
remove wheel
remove clock spring contact

install in reverse order

27 Nm for bolt

Make sure wheels are straight ahead and install steering wheel in center position lining up locking pins of fan fare horn and airbag clock spring contact

 

[jzchen]

Uh oh, mine does not have paddle shifters, that is why no mention of them....

 

[jzchen]

I don't believe you can just add the paddle shifters on a car without them. You will probably have to have it go through MB to have the SAM updated with a new tan code to enable the option.

No more TAN codes as of WIS version 9/2016.

 

[jzchen]

(I saw Brabus turbo parts on EPC, no code needed to upgrade between various programming/output!!!)

 

[jimvw57]

Hard to say what model car they have when they don't fill out the statistics page, or mention what model they are working on. DCO did say he has a 451 and his join date is Aug 2015 so I would believe he may need a TAN code.

 

[jzchen]

It isn't model dependent, or so I thought. Mercedes has done away with it altogether, with 9/16 software or later. I could be wrong...


Still need access to the machine though, or some clone version....

 

[DreamCarOwner]

Hard to say what model car they have when they don't fill out the statistics page, or mention what model they are working on. DCO did say he has a 451 and his join date is Aug 2015 so I would believe he may need a TAN code.

1. My 451 is a 2011. For the purpose of this post I didn't think the individual year mattered, sorry. Don't know what year the steering wheel is from. Bought it from a re-seller in E-bay and it was listed as 2008-2015 Smart Fortwo.

Now for a couple more dumb questions:

2. JZ when you mention a post on EPC, what does that stand for?

3. I understand what a TAN code is and what it does, but what I don't understand is.....when you need one as in activating paddle shifters or getting a replacement ignition key....why do the dealerships have to contact the mothership to obtain them ?

I'm going down to the garage shortly to switch out the steering wheel, so I'll document and take pics and post later on tonight. DCO

 

[jzchen]

Mercedes Electronic Parts Catalog. It covers both Mercedes and Smart. I bumped into pictures with turbo parts, shaded out, but still there.

I had a smarttekinfo subscription a week or two ago because water was leaking into my trunk and I thought I didn't have the spec for tightening the latch ring.

I am hoping I am correct, that TAN codes are no longer necessary from the mother ship, or a TAN code generator. At least that is what I read somewhere there....

There are no stupid questions, just possibly stupid answers. If one can't answer a question in a way the questioner understands, then you obviously don't understand the issue at hand. Or if you're like my old EE101 professor, "You ask the question, you give the answer!"

 

[Rustedwrench]

3. I understand what a TAN code is and what it does, but what I don't understand is.....when you need one as in activating paddle shifters or getting a replacement ignition key....why do the dealerships have to contact the mothership to obtain them ?

In previous versions of the Mercedes diagnostic software the TAN code was needed so the vehicle data card, or build sheet, could be updated in the Mercedes database so that any further parts search by VIN would return the correct result. The newer version of the Mercedes SDS, Xentry Tab, must be connected to the Mercedes server any time it is connected to a car so the information gets updated immediately. This not only applies to hard parts but also to software updates. If the server did not know that paddle shifters were added, for example, then any updated software would not have that capability. Then the vehicle owner would whine that his car worked before the shop worked on it and now it's broken. WAH! :crying:

 

[DreamCarOwner]

Well it's the next day...I didn't get this posted last night...Was sort of aggrevated and that was needless, but I will get into that further on down the "how to".

The first thing you will want to do is to unsnap the bottom half of the steering shaft cover. It just unsnaps when you gently pull down on it.



You will now need to unplug the 2 plugs that you see from the bottom.



For indentification purposes here is what both plugs are called.



Now you will need a #45 long shaft torx bit in order to loosen up the the steering wheel retaining bolt.



You can turn your steering wheel up to more comfortable angle to get at the retaining bolt.


I ended up using a 1/4" breaker bar, extension and a 1/4" socket to break mine loose because it was pretty tight and there wasn't alot of the bit hanging out to get a good secure hold on it.



Now line the steering wheel straight ahead and just grab the wheel on both sides and give a tug and it should come right off.



Lay the steering wheel face down on the workbench. Use a #20 torx bit and remove the two torx headed screws that hold the back cover on.



When you remove the back, the bolt that you loosened to remove the wheel will fall out. So be sure that you start it a thread or two on your 3 spoke wheel before you put the back on the wheel.

 

[DreamCarOwner]

Now use your #20 torx bit again and remove the 2 screws holding the silver plastic trim piece on the front of the wheel.



Now you can remove the bolts holding the air bag assembly to the steering wheel. I first tried using a 5.5mm allen wrench and removed the first one, but it didn't seem to go very deep into the head of the bolt. So I tried using a 5mm allen head wrench and removed the rest of them. It appears that a person could use a torx head on these bolts because they appear to be dual compatible.



Now you can separate the air bag from the wheel carefully. YOU NEED TO HANDLE THE AIR BAG CAREFULLY. The air bag contains a mixture of sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas and if for ANY reason it would detonate any body part within 10 inches or closer is guaranteed to be broken. The chances of it detonating accidently is pretty slim as it usually takes a minimum of 3 volts to fire one off, but just be careful and HANDLE WITH CARE......Now in the center of the yellow connector is a orange colored clip that can be carefully lifted out. The pink colored connector has a matching orange colored clip in it that you can also gently lift out. Then both connectors will lift off the air bag. Don't try to disconnect them on the clockspring end because they are really in there and I found no amount of prying and twisting would loosen them up without breaking the tab that holds them in place. You're better off leaving that end alone because you are trusting your well being on that airbag deploying in the event of an accident, so it is much easier to remove the plug from the air bag carefully, and when you re-assemble the plugs back to the air bag be gentle. Be certain you have the plug fully on the prongs from the air bag so you don't break the fragile orange clips when you insert them to lock the plug back in place.



Now for the black plug that plugs into the clockspring and runs to your horn. Now in my case I found the plug to be a very very contrary plug to get released so I could remove it. The area around the plug on the clockspring is very thin plastic so be gentle when you remove it. And now my source of anxiety on all of this. If you were lucky when you got your 3 spoke wheel this black plug came with your new wheel. Mine didn't, so now I am trying to get one sent to me from the resellers that I bought my wheel from. The plug with the 3 spoke wheel has the same 2 wires as the 2 spoke wheel. But the 3 spoke wheel uses the other 4 terminal spaces on that plug for the wires from the paddles. Yes the paddles use the existing horn wire circuit to the SAM. The SAM constantly monitors the amount of resistance in this circuit and depending on what that ohm reading is at an given second, it knows of you blew the horn or used either of the 2 shift paddles. It's very similar to what they did on the 450 with a little different means of execution.



One shift paddle uses a 2 wire plug and the other uses a 4 wire plug, so there's no mixing up your downshifts and upshifts !



Now the air bag assembly will bolt right up to your 3 spoke wheel just as it did on the 2 spoke wheel. The only difference in putting together the 3 spoke wheel is the mounting screws for the silver plastic trim piece is in a slightly different location from the 2 spoke.
Don't forget to start the retaining bolt for the steering wheel before you put the back on the wheel.

 

[jzchen]

My car came with cruise control, not paddle shifters. Are you going/able to add that, or is the Bus full with either device, shifter, or cruise control?

 

[OliverB]

Yep, 2013 had either cruise or paddles. I opted for paddles as most of my driving was local and I didn't need cruise.

 

[jimvw57]

nice write up and great pictures! you should come over and do the front end on my car... (then I wouldn't have to) I recall years ago (mid 70 ish) we used to have tech sessions in our Corvair club where we would meet on a Saturday and pull apart someone's car and add / modify something like this with about 15-20 members observing or helping. It was a lot of fun and we learned a lot. (and someone got their car fixed) Tech sessions were held at the GM training building which was nice we had factory support. We could pull the whole drive train in about 45 min!

 

[DreamCarOwner]

My car came with cruise control, not paddle shifters. Are you going/able to add that, or is the Bus full with either device, shifter, or cruise control?

I read in another post on the forum here that Neonspinazz posted. The European Fortwo could have cruise control and the shift paddles because European cars only have 4 air bags. The American Spec Fortwos have 8 airbags so we have to choose either cruise control or shift paddles. There isn't enough "channels" to the Sam. So we can blame the good old EPA for tht one. But you could order your's with shift paddles and then add an aftermarkewt cruise control like Area51 etc,...or at least I believe you can because I think the aftermarket cruise controls uses a connector to your ODBII port. I think my facts are correct on this. DCO

 

[jimvw57]

Aftermarket cruise controls wired directly into the computer (AreA451) and in line with the gas pedal (MDC) they did not connect to the OBDII port

 

[DreamCarOwner]

Aftermarket cruise controls wired directly into the computer (AreA451) and in line with the gas pedal (MDC) they did not connect to the OBDII port

Ok Jim thanks for the clarification on that. I stand corrected. DCO