clb0099

Hello all,

So over the last two months I been struggling with this no heat issue in my car and even brought to my mechanic who is also kinda lost as to why it only works while it only accelerating at 4k rpms and above. A list of parts that I have already replaced by me that were suggested by forum members. This is the list:

change over valve
water pump
radiator
Auxiliary Coolant Water Pump
upper/lower coolant hoses

Lastly I had the entire heating system flushed out and filled correctly.

My last hope is that it’s a part that some on the forum don’t think is on my car but is listed as a part on the star computer and one that was on the w220 that seems to control the heat flow at low speeds. The specific part I am talking about is located in the front passenger wheel well. Tomorrow I am going to attempted this post.

BOTUS

that's NOT the big valve on the ones with rear air con that I was referring too - if no separate rear heating / AC unit not sure why you'd even have pipes down there - did you look first ?

the new comment about now you have heat but only at high revs - suggests a circulation issue - likely one of these

so either the other electric pump is meant to run all the time
the water pump is defective
the flow is restricted due to a valve or blockage
a number of software bugs are making things misbehave

between kevm14 and I we have "just discovered" some oddities in the heater controls where they made 27,000 W221 cars with a button on the heater knobs that didn't work.... I think the issues came in with SAM updates - I'm guessing the later software engineers misunderstood interdependence between modules and BROKE stuff - as they never understood "improvements" in one modules software may upset code on the same can bus running in other modules and its crashing functionality or disables features

I DON'T think this post will fix yours - there are now so many faults in the cars knowing what to resolve is now hard work and NO one believes they EVER get things wrong... but the code comments I found in some modules discussing bugs and their bad fixes suggests otherwise....

https://mbworld.org/forums/s-class-w...ml#post8919607

my electric heated front screen ONLY went wrong after Dealer online tools updated the SAMs... I'm still testing a replacement Front SAM on OEM software I fitted last week, but its not yet got cold enough outside to switch on - my car is now using the OEM version changing back to 221 442 2100 of 05.46 from the last available update of 221 442 2700 all the way back in 06.26

it will be very interesting if my REST button NOW works as the car is back to build spec - on the F SAM and the Heater buttons

ALL USA cars should have fun as they got the car a year later "after Mercedes had updated much of the software" which now appears to be an incompetent muddle up of BUGGY VERSIONS EVERYWHERE CHASING THEIR TAIL TRYING TO FIX STUFF, IN ROUNDS AND ROUNDS OF INCOMPETENCE - and I'm now fairly sure ALL iterations of Facelift software (so 221 902 xxxx) in ANY module - its now cut down to bare bones jokeware losing much of the original cars features and refinements

If I'm correct the reason no one supports me on whether they have the "Nav overlay source Fade feature", is that many cars were built wrong with this broken / missing at build....

.

nath_h

This part was on 2007 S550 cars built before October 21 of 2007, so it's possible this is on your car. Rock Auto lists the cars up-to VIN.

https://www.rockauto.com/en/moreinfo...t=6860&jsn=490

clb0099

Botus,

water pump was replace as well as was the thermostat. I am being told by another of 07 w221 that he replaced the front sam and it fixed his issue. He said that he was getting heat only when he was at 2500 rpms.



QUOTE=BOTUS;8921571]that's NOT the big valve on the ones with rear air con that I was referring too - if no separate rear heating / AC unit not sure why you'd even have pipes down there - did you look first ?

the new comment about now you have heat but only at high revs - suggests a circulation issue - likely one of these

so either the other electric pump is meant to run all the time
the water pump is defective
the flow is restricted due to a valve or blockage
a number of software bugs are making things misbehave

between kevm14 and I we have "just discovered" some oddities in the heater controls where they made 27,000 W221 cars with a button on the heater knobs that didn't work.... I think the issues came in with SAM updates - I'm guessing the later software engineers misunderstood interdependence between modules and BROKE stuff - as they never understood "improvements" in one modules software may upset code on the same can bus running in other modules and its crashing functionality or disables features

I DON'T think this post will fix yours - there are now so many faults in the cars knowing what to resolve is now hard work and NO one believes they EVER get things wrong... but the code comments I found in some modules discussing bugs and their bad fixes suggests otherwise....

https://mbworld.org/forums/s-class-w...ml#post8919607

my electric heated front screen ONLY went wrong after Dealer online tools updated the SAMs... I'm still testing a replacement Front SAM on OEM software I fitted last week, but its not yet got cold enough outside to switch on - my car is now using the OEM version changing back to 221 442 2100 of 05.46 from the last available update of 221 442 2700 all the way back in 06.26

it will be very interesting if my REST button NOW works as the car is back to build spec - on the F SAM and the Heater buttons

ALL USA cars should have fun as they got the car a year later "after Mercedes had updated much of the software" which now appears to be an incompetent muddle up of BUGGY VERSIONS EVERYWHERE CHASING THEIR TAIL TRYING TO FIX STUFF, IN ROUNDS AND ROUNDS OF INCOMPETENCE - and I'm now fairly sure ALL iterations of Facelift software (so 221 902 xxxx) in ANY module - its now cut down to bare bones jokeware losing much of the original cars features and refinements

If I'm correct the reason no one supports me on whether they have the "Nav overlay source Fade feature", is that many cars were built wrong with this broken / missing at build....

.[/QUOTE]

clb0099

my vin#WDDNG71X67A031334.. does my car follow into that?

nath_h

You need to find the engine number. Go to LastVin and enter your VIN, and you'll find your engine number there. The specifics are as follows pasted from Rock Auto:

Through Engine# 30 196899; To 10/22/07; Including Engine# 30 200029; On Cylinder Head

clb0099

engine number 273961 30 016364

clb0099

So I fall into that category lol

nath_h

It seems you do. One more part to replace.

clb0099

thank you for your help

BOTUS

post #4 needs to put [ at the start of

to make it behave

BOTUS

oh no I'm right again.....

with an original 2005 Front SAM software iteration in there my REST button worked perfectly today !!!

its gets better - another (dodgy) early update was to improve the purple tinge on the early instrument cluster in cold weather - after that software update went on mine in 2019 I didn't get the extra units KPH to MPH menu I'd hoped, for but it wound the brightness flat out all the time - beforehand I could set day or night brightness on the rheostat whenever I wanted.... the update turns off daytime adjustment !!!

last week doing the trans fluid, I'd asked they officially SCN'd the cluster and it was bright and awful again and of course it turned on the stupid red petrol pump symbol - so as soon as I got home I threw that crap in the skip where it belongs - and re enabled the digital level menu - and then BY CHANCE I found an adaption brightness setting for the cluster hidden in another menu on the dealer tool...

this magically reset the brightness of the cluster from very high to normal during the day time.... and it had remembered it in three short drives ever since - which is nice...

Until today... started it up in reasonably bright weather - but time was latish and the auto time related madness for the comand screen menu swap, was already in play as the key went in (so black menus) and I noted the cluster screen brightness was quite dim !!!! 5 miles down the road I thought I better put the auto lights on (and the headlights immediately illuminated - saw on the back of the car in front)... so then I was finding the cluster was too dark. Tweaked it a tiny smidge and got things spot on, drove another 2 miles then suddenly the cluster screen when brighter than I have ever seen it, WTF and the rheostat would not change ANYTHING at all WTF - it was bonkers bright and getting dark outside, but not dark enough the night vision would switch - so now there are THREE different elements of the car trying to do stuff based on its interpretation of how late or how dark it is... insane when two of the three are using the same data from the same sensor ????

1) the COMAND uses TIME and the DATE to swap day / night menus (if using auto) you know this as the feature starts working correctly again after the clock fix update is applied
2) the auto lights (turned on)
3) the Night Vision knew it wasn't yet dark enough and refused to operate

So here I am cluster screen at burn out and yet no adjustability ... fiddled with stuff, light on off etc... nothing - parked up, key out, cluster bright as hell till it went to sleep

tested the REST button - immediately button light illuminates, hear the electric pump operate, then the vents clunk and whirr and the blower motor is running (heat out of vents) switched it off, lock the car go shopping....

get in the car drive off then notice the cluster screen is super dim had to wind the brightness up a smidge WTF.... 1/2 mile up the road screen looks like its misting up WTF - oh - now what - no air to the screen, can't be only ever have three big arrows (all vents always open)... look to fiddle with heater controls

magic its switched its self to min fan speed both sides and all air to the floor both sides.... never ever done that in the 9.5 years I have had the car.... WTF

so either - it has a default REST set up (and that's the default), but if so why the bug on start up (shouldn't it have gone back to user stds)

OR and more likely the software was a bunch of halfwits with NO IDEA WHAT THEY ARE DOING - like I keep suggesting

you're going to like the next bit - that old Front SAM software has got ONE of the noise sources remembering the Nav Fade overlay feature like I remember it

clb0099

Botus,

when you speak that you replaced the front sam is that mean you replaced both pieces if it. One piece is for the all the fuses and relays. Then bottom piece is actually the “Sam” which is programmed to the car. I bought just the top piece from Mercedes which was remanufactured. Also that valve I posted in this thread of posts.. well it doesn’t go on my car as I took off the front passenger rear liner and there is no duo valve.

This is not the exact part I got as this is used. I bought my part brand new from the Mercedes dealership.

This is actually the part that holds all the programming and the other part is called the “ Base” it’s just holds the relays and fuses. The “base” is usually what goes faulty after while.
.

i am only left with redoing 2 parts which are the thermostat and the water pump.. even though those are not even a year old

Final thing is that the pipes coming from the heater core are hot.. not sure why it’s not pushing heat out

BOTUS

your circled bit above is the Front SAM, your photo is of the SRB, your part supplier is using the wrong naming terminology - its exactly the same in the boot - (many don't realise on the main SAMs these two units unclip and come apart) the R SAM (H SAM in German) and the SRB - H (signal relay board - hinten, as in rear) is the fuses, relays and big boy wiring... its the SAMs that holds software and stores specific vehicle config and any error info and has fewer connectors

the industry is moving to confuse Mercedes owners, now calling SAMs the Body Control Module (BCM) ...when Merc already use that acronym for battery control module...

whether to fit both the SAM and the SRB depends

1) Mercs are so unreliable - carrying / having available major spares is always a sensible precaution - you may need a SAM every time you reach for the key !!!

2) I just wanted to leave my F SAM module as is - with its current software (latest update) installed and fully SCN'd Online - so I can swap back and forth between software iterations to test what Merc never understood - especially as I am fed up with garages that have no idea telling me I'm the idiot - the last thing needed in bug fixing is to be muddling up coding and introducing errors you don't realise you put there

So for me wasting time changing the top bit (AKA the Front SRB) and the SAM together is a mistake - but if you believe / know yours got water / crash / vandalism / bad workmanship / age related wear or damage AND you know the SRB you are fitting is 100% viable you can do either - but boy its a lot of extra wires to fight swapping both the FRONT SRB and the SAM together...

Although remaking each connection of the plugs around any module when you can reach them is a good idea (so long at you fit things back with wire routing better than it was made, and of course never damage any retention clips). I always remake using something like ACF50 to stop corrosion. I do it popping a plug one by one and a quick squirt, as its not muddling the rats nest of hell till you snag it up so they don't sit nice and you don't forget to plug one back in as you can't see or reach anything at all when it comes to how the fit SAMs in these cars - by doing so, you also get to remove that little bit of resistance 10 plus years of corrosion and time brings to the party to make Canbus systems start lying.

Don't forget if you are doing both you must check every single fuse and relay are functional and in the right place and remember you are disturbing lots more connections - did it in a rush of her Ford once - had planned to do nice and steady and follow a sensible process in broad daylight - but after fitting it at the place where I had time and space, I ended up without my PC to code the config over...

somewhere else, the next day just as its getting dark I ran out and threw in the new one yet again, whilst I could just make out the where the plugs go in. Connected the battery - and the headlights were on and the headlight switch unresponsive.... now I was panicking as I couldn't get it on a power supply and the headlights are full on (I didn't even have a torch to see which fuse to pull), even the laptop wasn't fired up yet... luckily on a PROPER CAR you just flash the config files across and set things up like a grown up in seconds - it not pages and pages and multiple menus of muddled German gibberish taking an hour or so

but then the flipping car wouldn't start !!! WTF - by now it was nearly night time and trying to rain, I was parked where I shouldn't be and so had to throw the old module back in quick so I could move the car !!! I couldn't for the life of me get why it wouldn't run with a fully configured compatible part ...so now what - Parked it somewhere sensible (still on the old module for the second time in a row) I gave up for the day and had a tea, and I started to think what I might have messed up... then it dawned on me. The day before when I had the time and space but had forgot the laptop - I'd never got round to checking the fuses !!! So one by one (lots more fuses on the Ford one) everything was present, correct and working - until the very last fuse I came across, just wasn't there... Run around on the internet trying to find a fuse diagram - its the flipping fuel pump fuse !!! - the donor part came from a diesel and I was putting it in a petrol that has a pump - had I not been so stressed and confused about why the headlights were jammed on, I would have remembered it had fired up (on its residual pressure in the fuel rail) when I first saw the lights flattening the battery - but only for a split second - so there was never any coding or immobiliser fight I was stressing I'd gone and messed up... the headlights issue was just autolights on her car and manual on the unit I was fitting - with the laptop loading the correct config for her car, battery on next round and all is good with life..

ANYWAY cautionary tale over...

its quite a good idea to buy both parts secondhand if cheap enough (as many don't realise they unclip apart and are two separate components ) - you get some spare fuses, usually a load of multiplug pin bush housings (as they mostly cut looms), some relays that might be usable in an emergency, and even a part you might need one day - but unless you like to introduce more hell in your working / diagnosis fight, just do the SAM

the one I got is still the current spare part number, and it was running the software iteration I was after - even ALL the coding was set up correctly - but it claimed to have come out of a 320 CDI... had some interesting errors in its memory... and three key fuses popped, ISM, EWS and the Cigarette lighter - so no wonder the car got dumped, it would have been a non runner with those fuses gone - and the errors where Coolant pump dead, ISM dead, EWS playing up, REST playing up !!! oddly seems it might have been a newish part ! as one print out I checked I believe says its a 2021 aged part - and when I popped it out of its case before fitting it did look like a brand new board

REMEMBER - if it got parked in a puddle Mercedes made sure it was the critical module that gets wet first at BOTH ends of the car (AKA the SAMs sit ready to get wet first), after all you wouldn't want just a damp fuse when you can destroy a circuit board at $500 to $800 and make sure it won't start, would you

.

clb0099

nath,

I checked the front passenger wheel for this part and no good. Do you actually know where it’s located?

nath_h

Not sure, but the following diagram shows it grouped with the thermostat and water pump, so probably close to those....

https://mbparts.mbusa.com/oem-parts/...lve-2722000031

BOTUS

as per the other post by kevm14 the part you found was an e class and here the drawing says C300, c300 4-matic. 3.0L. 3.5L v6. C350. 2008-11. 4.6 & 5.5L.


this is the std w221 set up


this is the ALTERNATE set up if you have the option of separate Rear AC - which adds the valve at the back of the wheel arch Part 420