spr

oh. My right passenger side control doesn't do anything no matter auto or manual. The left driver one however controls the direction just fine. That's a bummer that they don't work independently girls would love that.

BF_JC230

Yes – The passenger side will not work independently of the driver’s side – because if you only install the digital screen HVAC control unit (N22) you will not have the dual fans that are located in the heater box…You will also not gain features of Thermotronic – you will still have Thermatic with a new control unit (That looks WAY better!)

To have REST work you also need a few things stock – or added…

(580) Automatic air conditioning
(875) Heated windscreen washer system

- I read that you need to hook up a “no load current retention unit” when you make the swap – did you guys do that – or just unbolt, unplug and then install?

REST needs to be variant coded and is code…

(670) residual engine heat utilization system

SPR – Can you please share your Part Number?
Thanks,
Jake

- Also – can the two of you PLEASE post a picture of what you had in your car stock? HVAC control unit design (A) or (B)….Thank you!

PNs PNs PNs...

BF_JC230

OR...Maybe it is possible to add in REST with the dial controlled Thermatic controller....Interesting - Not nearly as cool as what it should look like STOCK - but could gain the feature...

Jake

spr

I'm pretty sure I don't have to add anything for rest as I was already told it could simply be version coded. I just plugged mine in and it works just fine, I didn't have to modify anything.

Maybe. I know that the US knob one I had didn't have it marked rest, so I don't know if it has that circuitry inside to enable it. I can definitely say that the temperature is FINALLY what it actually says it is. The knob controller is just a POS. That was my main requirement. Rest will be enabled just because. The separate fan control for the passenger would be nice for girls but I don't really care.

I recieved the same unit P/n as RW.

BF_JC230

What did you (both) have STOCK as far as the [A/C] button?

This is what I have, what I picked up – and what I am thinking I should get to make the A/C compressor cycle happy…Unless the HVAC control unit will know the difference in the LED illumination logic between [A/C] and [AC OFF] and when to run and not run the A/C system…

Any help would be great!
Thanks,
Jake

crazeazn

all those guages all look same at cursory glance.

BF_JC230

Well that is part of the joy of M-B...Things can look the same, and be a tad different and then be a lot different at the same time!

- Well I will say that my dad and I installed the unit today (A203-830-19-85) into my car and this is what I am learning in a short amount of driving / using...

I have the M271 with the 6 Speed Trasmission and I feel I need to have the REST button programmed as the A/C compressor seems always on, when I push the button to ask it to be on or off - it seems always on.

ALL other functions are working as the original turn dial did - I can control fan speed, temperature, fan / blower placement and the passenger side dial for heat location I did not touch. TUNNEL MODE works and the front defroster seals up the other flaps and blows hard on the front screen - Although it does feel a tad cool - getting back to the A/C Compressor possibly being on...With the dial unit when the A/C was ON you really felt it in the clutch pedal and how the car would be down on power - not so much now - you "kinda" feel it is a little down on power - but clutch feel is almost the same - the only way to hear the engine "Pirk up" is to turn OFF the HVAC control unit - then there is a clear change to the engines tune...

What I have read - and my logic for going with A203-830-19-85

1. This P/N is for the N. American market
2. Display Logic for LED in A/C button / REST button; On vehicles up to (My car 11/30/04) 5/31/05, the function LED is ON when the compressor is OFF. On vehicles from 6/1/05 the function LED is ON when the compressor is ON.
- This does not follow the logic in my car with unit A203-830-29-85 where the light in ON for the compressor to be ON - It does however follow this WIS logic.
3. Try it and see if it works - and it seems like it is very close to being 100% what I want.

For those of you that THIS DID NOT WORK - what did not work - the whole thing, fan control, temperature setting, etc?

Thanks all,
Jake

BF_JC230

Here is a picture…

No Ashtray with 12v plug in and Digital ACC with REST.

I will let everyone know how STAR programming goes when completed!

Please post what you know on this modification / upgrade / retrofit…
Thanks,
Jake

lkfoster

That's what I'm looking into also. Up to the mid-life model refresh you could get a dial control unit (code 580) with REST (code 670), but nothing shows after 2005+ in the EPC. Then again, the REST code doesn't show for the digital (code 581) control unit after 2005+ so who knows.

My wife is having Steve make some version coding changes on Wednesday and I'm going to see if he can turn REST on with the original dial-type control head.

BF_JC230

They make it difficult - no doubt...

Please keep us informed and thank Steve for any information - He and Wanda are always most helpful!

Thanks,
Jake

BF_JC230

Well I thought for fun it has been more than 24 hours now - I will try the REST feature...And with no key in the car, or in the ignition - I pressed the button - held it for a second or two and air began to blow out of the duct work and the AC OFF / REST button light came on.

Jake

lkfoster

Steve tried it and it didn't work. It was worth the try though.

BF_JC230

This is a HIT OR MISS item - a few people have reported NOTHING working and the swap failing - I hope I am 'Hitting" as everything seems to be working - I just want to CONFIRM the A/C compressor is cycling corectly with the [AC off REST] buton.

Any information on this would be GREAT!

- I have been getting some PM's on this...so here is my "answers"...
Thanks all,
Jake

Hi,

I have posted all the information I have on this swap - I bought PN 203-830-19-85 because my build date required in WIS that the AC LED be ON when the compressor was OFF.

It is EASY - The hardest part is NOT TO CROSS THREAD / OR MAKE NEW THREADS in the plastic bosses when you re-install the torx head screws. Have a magnet under the hardware so you don't lose anything in the tunnel. Make sure you feel the threads start in their FACTORY races.

1. Pull up using a soft tool wedge to start the front edge of the console cover.
2. Dad and I removed the snapped in ashtray to swap to smoker delete
3. Locate lower HVAC controller torx head screws (on an angle!) and remove
4. Unsnap GENTLY the HVAC controller from the edges
5. Pull unit from console
6. GENTLY push in tab on main plug, swing clamp (grey) to disengage - disconnect plugs.
7. Reinstall insuring that you take your time, snap in the items to clip and do not cross thread your bosses!

See here!
Thank you to ORIGINAL Poster Sanf! (In DIY Sticky of the w203 forum)

https://mbworld.org/forums/showthrea...=1#post2264959

Good luck,
Jake

BF_JC230

6/1/05 and later have LED on when A/C Compressor is ON

These are USDM builds...
Jake

polo

I would like to do this mod but I do not know who steve is and how to contact him so I can buy the unit. Can someone please pm me or post how I can contact him. Thanks in advance.

BF_JC230

http://www.mbenznl.nl

have fun! - Mine is A okay - STAR checked out GOOD TO GO!

polo

Thanks BF for the link I just emailed Steve I hope I can install it I looked at the diy that was linked to this thread but it seems like that person was doing other things to his car. Do you really have to remove the whole center console from the arm rest to the vents just to swap the climate control? Also if you don't mind me asking how much did they charge you for the star coding and what exactly did you ask them to do.

Thanks again

BF_JC230

No...You don't have to remove everything...

My father and I had this changed over in no time...It may be a smidge easier on my car with the manual transmission, I have no [P N R D L] cover to remove – the shifter boot just pulls up!

1.) Put car in neutral or 6th gear
2.) With a non-marring soft tool pull up the front edge of the console trim cover – it is held in with two snaps
3.) Gently pull it forward and up – mine did not completely release from the arm rest area – but did give enough of an angle to do the work
4.) Unsnap and remove the ashtray and cigarette lighter
5.) Unsnap the cover and slide it off of the folding tray / lid
6.) Install your lid onto the new Smoker Delete tray A203 680 52 50 Paneling
7.) Look low and in the corners of the HVAC controller and remove ON AN ANGLE the two small torx screws – they are in TIGHT…take your time – don’t smack your interior and apply good force on the screw head as you twist to remove
8.) Be careful! The font clips holding the console trim are thin and sharp
9.) The HVAC controller is screwed in place on the bottom – and snapped in the upper sides…undo the snaps (Gentle…don’t kink or scratch your trim!)
10.) Unplug the HVAC controller by gently pressing in the snap on the main harness and swing down the retaining clip – then unplug the two harness ends
11.) Reinstall and function test your new HVAC controller before you button it all up!
12.) INSURE that you are going into the factory threads when re-installing - DO NOT CUT NEW THREADS IN THE BOSS!

Good luck,
Jake

polo

Wow thanks for the walk through and the pictures that should help me out alot. I emailed Steve and Wanda emailed me back and said that the transfer very rarely works on cars 05 and up. She siad Steve has tried to install 15and only one or two of them worked. It is a huge risk but I am going to give it a try Wanda said they do not have any but they would try to get one. Thanks again for all you help.

Regards
Carl

BF_JC230

Yes - they are great - I have never dealt with Steve - have had a few emails with Wanda - Very helpful and informative!

Yes - ALL of my research has proven that this is a hit or miss...it took me a little while to pin point what PN I needed for what build date and what market...But it is working!

You are welcome for the images - that is what these boards are for - to share information and help each other out!

Homework always pays off!
God luck,
Jake

polo

Hi Jake, Steve is trying to track one down for me. I have one last question which pn do you think I need my build date was 11/05. I saw the two pics and pn you posted in this thread for late 05 and early 06 models do you have any idea which one I might be better off going with.

Thanks
Carl

BF_JC230

2. Display Logic for LED in A/C button / REST button; On vehicles up to (My car 11/30/04) 5/31/05, the function LED is ON when the compressor is OFF.

On vehicles from 6/1/05 the function LED is ON when the compressor is ON.

I do NOT know what PN you need...Steve should be able to track that down based on his record...I would think you have a [A/C] button with no [REST]...
Good Luck,
Jake

maverik259

plus the one i am picking up doesnt say rest on the bottom right button...it just says A/C...its model numer 44 85 not 43 85...does that mean anything?

maverik259

in fact this looks like the model I am attempting to acquire...how is this different from yours or the other model? and as I've been reading I can't seem to undertake what the REST function actually accomplishes? i live in maryland most the year so it gets cold and you said you bought for the cold weather so you could use the REST feature. So how will this help with the cold?

Thanks!

lkfoster

The REST function runs the heater fan and a coolant pump for 20-odd minutes after the engine is switched off to blow hot air into the cabin.

I've also heard, but cannot confirm, that it works the same with cool air using the thermal mass of the AC evaporator.