ASC / DSC switch swap

[Dino D]

Hi All,

I am in the process of swapping over the interiors - my 2.8 1998 tan interior is being swapped with a 2002 facelift 2.2 interior.
So far with help from threads on here and elsewhere I have done the seats (and got the pre-face lift wiring to work with facelift seats so now heated) and door cards and have the consoles out on both cars.
All the switched swap fine except for the ASC / DSC switch.

My car has the older style ASC switch which has 6 pins in 2 row configuration. The newer style DSC switch to match the new console has just 4 pins.

Anyone done this swap and made it work? Ideally I would like a switch that says ASC but in the new style (and of course wider to fit the holes in the console) but not sure if such a thing exists?

[steve f]

Both the ASC and DSC switch should just push out of the switch panel. Both would have the same size mounting. You will want to mount the ASC control switch in your car.

The DSC employs a more involved system including steering angle and yaw sensors that were not in the 98s.

[lokijibber]

Actually, there is a ASC button available in the facelifted style. I have one at home. I'll check the # of pins on the back - thinking now that its 4....

[vanne]

Regardless of the operation of the system, it's just a on/off switch correct? Should be able to turn the system on-off with the switch regardless of the system it controls???

The reason I piped in is I have a 2002 center console on the way myself to freshen up my coupe a tad. I know I'll be soldering thewires for the switches, but am assuming they are all just on off switches???

[Dino D]

Thanks for the replies.

The problem is that the preface lift ASC switch is in a narrower housing than the DSC switch and so will not fit in the cutouts of the new dash. In addition the old style switch looks ancient especially when laid out next to the newer style buttons I have for the heated seats and ac.
I don't want to move the ASC switch to back either.

As the above poster pointed out ASC is different to DSC- from a switch pint of view I think the difference is that DSC is 2 stage (depending on he long you depress the button) and ASC is simply on off. Not sure why the
'simpler' system has more wires though.

I'm not looking to change the system just want a button that looks and fits right in my dash.

Next problem will be how I fit the wider DSC switch into the old console that I am putting into the donor car before reselling...

[vanne]

Let us know if you get it to work as next week ill be doing the same job as you... And yeah don't wanna use the older buttons...
Btw can u take some pics of the airco and seats switches at the back which wires you connected where so I don't have to reinvent the wheel. That would be great!

Cheers
V.

[lokijibber]

The post-facelift button is also 4-pin -CONFIRMED

The PN on the one I have is: 8 381 971 (not sure the part-group prefix for switches, but I'm sure you can find out on RealOEM). This particular one also has a build date of 8-6-99 if that helps you at all. I researched pin-outs of this switch when bought it. I am only intending to use it for powering sport mode, so not too detailed, but from my notes, I have the following:

1- switch
2 - Ground
3 - PWR
4 - switch

[steve f]

Regardless of the operation of the system, it's just a on/off switch correct? Should be able to turn the system on-off with the switch regardless of the system it controls???

The reason I piped in is I have a 2002 center console on the way myself to freshen up my coupe a tad. I know I'll be soldering thewires for the switches, but am assuming they are all just on off switches???

Looking at the wiring diagrams in Bentley (page ELE72), it appears that the 1998 ASC switch is an on/off has four connections (1) from the power distribution to (2) the ABS/ASC control module, (3) from the light switch (to illuminate the switch), (4) to ground.

The 2002 ABS/DCS MK (page ELE85) also has four connections in a similar configuration to the switch. The switch is identified as momentary. That would make a huge difference. You should be able to sound it out to confirm.

Bentley has been known to have errors.

Another possibility is to move the ASC switch to the unused switch blank that is just inboard of the steering column. That blank is a smaller opening.

[Dino D]

Thanks for that lokijibber.
So that means I won't be able to simply plug in a facelift ASC switch into my car...I wonder if the wires can be combined into 4 so as to fit. I saw a pinout on a post somewhere comparing both so will dig that up.

Let us know if you get it to work as next week ill be doing the same job as you... And yeah don't wanna use the older buttons...
Btw can u take some pics of the airco and seats switches at the back which wires you connected where so I don't have to reinvent the wheel. That would be great!

Cheers
V.

Hi,
I don't have any pics but it's very straightforward:
The aircon switch was a straight swap over from old to new.
For the heated seats it's a straight swap too unless you don't have them currently-in that case you just have to dig around the gear lever or bottom of console area and you will find the plugs tucked away (I believe all cars came wired for heated seats already so the wires are there).

Ps: good thread here: http://forums.bimmerforums.com/forum....php?t=1620196

Myredzed has made some great posts with pics too about swapping consoles - if he's reading thanks!

[robrez]

You can re-locate the ACS switch. It should fit in the narrow switch opening next to the steering column. My oem alarm LED is fitted in the slot.

[myredzed]

The answer to the pre/post facelift ASC switch problem is here. The contacts (sockets) in the connector are the same for pre and post facelift so all you need to do is remove them from the pre-facelift connector and push them into a post facelift connector using the idents identified in the link above. The post facelift connector you need to fit into your new switch is item 4 on this diagram

Also to confirm that a post-facelift ASC switch does exist:

Myredzed has made some great posts with pics too about swapping consoles - if he's reading thanks!

I am reading, thanks for the appreciation

[vanne]

Okay, so if your trying to connect the older style 6 wire/pin asc connection to a newer style 4 pin /asc switch, then what goes where? And is the new 4 pin switch an on/off switch or a momentary switch?

[myredzed]

Okay, so if your trying to connect the older style 6 wire/pin asc connection to a newer style 4 pin /asc switch, then what goes where? And is the new 4 pin switch an on/off switch or a momentary switch?

Just re-read my post and all the other posts too - agree that it's all a bit vague. I can't remember exactly which thread I followed when I did mine so for clarity I'll take a piccy of my switch and connector set up at the weekend.

Not sure what you mean by on/off vs momentary switch. With my set up when you press the ASC switch you get the amber light on the dash and no ASC function, when you press it again the light goes off and ASC is enabled. The ASC on/off functionality definitely works, I've tried it

[vanne]

Sweet mate, a pic is worth a thousand words

[BenFenner]

Also to confirm that a post-facelift ASC switch does exist:

This is special? I have one on my 2000 Coupe. =]
Not a DSC button, but the ASC button.

Push once to deactivate ASC completely (with light showing in dash), push again to activate. (It is active when you start the car obviously.)

[khammack]

Not sure what you mean by on/off vs momentary switch.

With an on/off switch the connection stays on/off depending on the position of the switch. On a momentary switch, each time you push the button a pulse is sent to the ECU which will then do what it needs to do, either turn something on if it is off or turn it off if it is on. The DSC and I think the ASC are momentary switches.

[lokijibber]

^^^Correct. That's why I intend to use it for sport mode. Definitely momentary switches. The "+" PWR is only used for illumination

[myredzed]

I'll take a piccy of my switch and connector set up at the weekend.

Until I get chance to take a piccy I've revisited my initial research from Bentley and I think this will help the OP too:

On a pre-facelift switch there are 6 pins on the switch however only 4 are used as follows:
Pin 6 - ASC switching signal
Pin 4 - Ground
Pin 2 - Lighting
Pin 5 - ASC power
When the switch is operated it routes power from pin 5 to pin 6

On a post-facelift switch there are 4 pins, all are used as follows:
Pin 4 - ASC switching signal
Pin 2 - Ground
Pin 3 - Lighting
Pin 1 - ASC power
When the switch is operated it routes power from pin 1 to pin 4

In order to get the later switch to work in an earlier car you just need to ensure that you move the sockets 1 at a time between the old and the new connectors i.e.

Pin 6 to Pin 4
Pin 4 to Pin 2
Pin 2 to Pin 3
Pin 5 to Pin 1

HTH

[Amuro Ray]

Why not just use an M roadster switch? The prefacelift M cars all had ASC and the round buttons.
Looks like you're driving Pangsters(sp?) car now too?

[myredzed]

Why not just use an M roadster switch? The prefacelift M cars all had ASC and the round buttons.

Are you sure about that? I didn't think the pre-facelift ///M cars had any driver aids aside from ABS and the wiring diagrams appear to back that up. Bentley shows post 98 ///M cars with an ASC switch having 4 sockets labelled 1 through 4.

[Amuro Ray]

Are you sure about that? I didn't think the pre-facelift ///M cars had any driver aids aside from ABS and the wiring diagrams appear to back that up. Bentley shows post 98 ///M cars with an ASC switch having 4 sockets labelled 1 through 4.

Option on 98 models, standard on 99 (which would be prefacelift) all 99-00 M cars (US spec) should have had ASC. When the S54 Came out it was changed to DSC, non M cars got DSC in 2000.

I could be wrong, so feel free to double check.

[vanne]

Myredzed, thanks heaps for the pin outs mate, that will make things much, much easier.

[myredzed]

Option on 98 models, standard on 99 (which would be prefacelift) all 99-00 M cars (US spec) should have had ASC. When the S54 Came out it was changed to DSC, non M cars got DSC in 2000.

I could be wrong, so feel free to double check.

That seems correct. Bentley shows 98 ///M cars with and without ASC switch on wiring diagrams. The switch has the same pinouts (1 through 4) in all diagrams for the ///M and is the same as post-facelift non-///M zeds ASC switch.

I'm getting a bit mixed up with my pre and post facelift dates I think!

[Dino D]

Thanks for the all the details! Will make life allot easier.

I have fog light switches next to the ignition so can't go there. I might tuck the ASC switch in the side of the boomerang until I can get a proper facelift ASC switch.

Now have to find the time to do it all!
Managed to get the sports heated seats and console in. Can't believe the difference the seats make and the heaters are great in this weather. Really glad I've bit the bullet to this mod and all the associated work!

Will be doing it again once I find a cheap M console but next time around will be super easy no the harder work is almost done!

[myredzed]

As promised some pictures for going from pre-facelift ASC switch to post-facelift ASC switch:

Pre-facelift ASC switch and connector at the top, post-facelift ASC switch at the bottom:


Post-facelift ASC connector wired in to pre-facelift ASC loom (rather conveniently the contacts on the wires from the pre-facelift connector slot right into the post-facelift connector - no new cutting or terminating required, you just have to get each wire with the contact still on it out of the pre-facelift connector and push each one into its new position on the post-facelift connector )


Post-facelift ASC switch connected:


Simple!