W215 Battery Drain

Discussion in 'Electronics' started by rk100, May 15, 2015.

  1. rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Hopefully some of the electric wizzes on here can help me out!

    I have got the dreaded battery drain issue in my CL. At first I thought it was just my battery going bad so got a new one at the dealers. Fine for two days than it just dead. So got myself a little fuse blade meter from Maplin and set about checking each fuse - of course I left the necessary areas open and locked the car and waited 30mins before checking the fuses. From looking about on the internet it appears that a draw of 50ma to 65ma could be normal for the w215's . Anyway Fuse 82 which I understand covers the following:

    • AAC[KLA] control and operating unit (N22)
    • Heating System Delivery (A31)
    was pulling 1.26a - so I think the issue is with this one as the combined ma of all the remaining fuses equated to 62ma. Does anyone know what the two items in the points above are/control and what in them could be causing the issue. Any help and comments very welcome
    Thanks
     
  2. mercedescl500

    mercedescl500 Hardcore MB Enthusiast

    Messages:
    816
    Joined:
    Mar 28, 2008
    Location:
    West London
    Car:
    CL500 with Brabus Bits and 1 Big Suprise
    At a guess I would think the Keyless Go is not going to "sleep". Are you opening and closing via keyless go ? Have you tried only locking and unlocking via the normal key ?

    Please disregard this answer. I'm obviously on another planet right now. Apologies.
     
    Last edited: May 15, 2015
  3. Dec

    Dec Hardcore MB Enthusiast

    Messages:
    4,475
    Joined:
    Jul 28, 2004
    Car:
    C180,A.
    There is a coolant recirculation pump in the engine bay that might be suspect.

    With the engine up to normal working temperature, open the bonnet and then lock the car with the remote fob… the car alarm won’t go off… then listen and feel the pump to see if it is running 5 or 10 minutes after the car was locked.

    Example of pump… E200 pump draining battery - Mercedes-Benz Forum

    Dec
     
    1 person likes this.
  4. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Anyone?
     
  5. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Thanks Dec - just seen that after I posted there now
     
  6. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Anyone else have any ideas on what could be pulling power from either of these two items?

    AAC[KLA] control and operating unit (N22)
    Heating System Delivery (A31)
     
  7. martyz

    martyz Hardcore MB Enthusiast

    Messages:
    2,370
    Joined:
    May 14, 2011
    Location:
    New Forest
    Car:
    '99 S202 '91 W201
    Air conditioning Control unit N22 (AAC pushbutton module)

    should show code B1000 if defective,suggest you get it hooked up to Star for diag.
     
    1 person likes this.
  8. Auto-mobile

    Auto-mobile Hardcore MB Enthusiast

    Messages:
    1,600
    Joined:
    Oct 1, 2011
    Location:
    Birmingham
    Car:
    2x c43 Amg clio 172 turbo 314bhp
    The drain needs to be check properly with a multimeter inline on the battery, check for water ingress in passenger footwell, previously I have seen the rear Sam, upper control unit (lamp unit) sat Nav and seat control units cause a drain that will kill a fully charged battery in 2 days.
     
    1 person likes this.
  9. design guru

    design guru Hardcore MB Enthusiast

    Messages:
    400
    Joined:
    Feb 28, 2004
    Location:
    Hampshire
    Car:
    2001 W220 Mercedes S320cdi
    I am sure you did the obvious, but did you reset the electrics when you put the new battery in? My W220 had a faulty passenger seat control unit which cause meant the seat would not move or the indicator in the mirror did not work and once replaced and electrics reset it was fine, does you door control modules both work?
     
    1 person likes this.
  10. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Yep reset the electrics. Door modules are both working
     
  11. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Thanks. When you say needs to be checked probably with a multimeter inline do you mean the blade fuse reader would not indicate the correct fuse pulling the power? When I checked them all with the blade fuse reader it was the one I noted in my first post that was pulling the power. I am not an expert in any of this so just asking - will the multi meter show me better information/indication of the issue. To be honest I though it gives the same as the blade meter with the only difference being that you don't have to go back and forth every time to check the meter when taking out a fuse.
     
  12. Dash1

    Dash1 Hardcore MB Enthusiast

    Messages:
    228
    Joined:
    Nov 9, 2010
    Location:
    Merseyside/Staffordshire
    Car:
    2013-Audi A8L (W12) Exclusive (D4) 1998 H-D FLHTCUi and FLSTS 95th Anniversary Models.

    Hello Ray,

    Auto-mobile doesn’t actually mean what you are suggesting, what he is referring to here (quite correctly by the way) is that all the parasitic/quiescent drain needs to be measured as a “global” figure, rather than a single isolated component figure, and that can only be done by one of two methods using an ammeter. Firstly, by disconnecting the vehicles negative battery lead and inserting an ammeter in series so “all” the current is measured when “all” the vehicles modules are in “sleep” mode, and secondly, you could use a clamp-on ammeter, not quite as accurate as the former but simpler to use without breaking in to or interrupting the electrical integrity of the circuit. There is actually another way in the absence of an ammeter, but you would need to place a fixed 1 ohm x 10 watt resistor in the circuit and then measure the voltage dropped over the resistance and then calculate the current draw from the figures obtained, that’s not as difficult as it sounds, its really very easy and a method some people prefer to use anyway.

    By the way, 0.047 amps (47 milliamps) is the maximum permissible parasitic/quiescent current draw on a CL, calculated on and from the engineering data given for each modules parasitic limits - times those limits by the number of modules on the car and its easy to see where the maximum threshold limit should be. Yours being the CL65, further and slightly complicates matters here with the integration of several supporting systems. I would imagine that it does have everything on it, so anything in excess of that figure of 0.047 amps should be considered as being “suspect”. The figure of 1.26 amps obtained from that particular circuit alone that you refer to be excluding any other parasitic drains within the remainder of the electrical system does seem to be relatively high and does need investigating. There could very well be some other underlying issues here and the vehicles systems need to be checked out properly – speculation and guessing on these cars could prove to be very costly.

    The AAC or ACC systems, like most electronic control systems on a modern motor car, have sub-systems and often a component in the sub-system can give rise to a fault with does in fact affect the main or primary system. The climate control system on your car is slightly different to some of those, in fact, fuse number 82 is considered as the main input supply voltage, however, the sub systems on the CL’s are powered up primarily from the head unit and it could very well be that there may be an issue here. Before you start to look for any issues elsewhere, it might be advisable at this state to interrogate the AAC control module and extract any fault codes that may be stored in there. Follow this procedure Ray and then come back to me with the fault codes, if any, and we can look at those first.


    • Start the vehicle and then switch on the AAC system by pressing the button marked as “O” on the right hand side panel at the bottom, now hold down the switch for the activated charcoal filter at the bottom left hand side of the left hand panel and at the same time hold down the switch marked as “REST” at the top in the right hand side panel. Hold both of these switches down simultaneously for between 5 and 10 seconds until you see the word “searching” appear in the panel display in the centre of the AAC screen.


    • When the diagnostic procedure has finished, you will see the letters marked as DIAGN. ERROR” and the symbols marked as “- - - -“ appear, this means that there are no fault codes actually logged and we can assume from this that your area of concern is somewhere else and not down to any specific component in the AAC system. If any fault codes are logged, then write them down so we can look them up to identify the component/s. It will only show one logged fault at a time, so you can scroll up or down with the temperate control toggle switch on the right hand side of the middle paneluntil you have identified all the fault codes logged.


    • If you want to clear any fault codes, then just press the centre button in on the left hand side panel marked as “AUTO” first and then do the same on the right hand side panel marked as “AUTO”. The codes will now be erased. If there is a “hard” fault within the system, then when you come to do another diagnostic check, the fault code should come back


    • To come out of the diagnostic mode sequence, then just press the “REST” button on its own to display the normal window in the centre panel display. Turn the car off, wait several minutes and start the car again if you wish to go through the procedure again to confirm if any codes are now stored.

    In answer to the specific question you raised above “Does anyone know what the two items in the points above are/control and what in them could be causing the issue.” From the head unit itself, which you have identified as N22, then the power is supplied from this unit to the stepper motor electronics control module; centre ventilation electronics control module, the sun sensor and the multifunction sensor, to name just a few. There are quite a lot more units involved other than these here Ray that are in fact networked over the data bus (CAN) to various other modules, so all in all, a very very complex networked system.

    The other item that you have identified as being A31, well, this unit is actually the heater supply unit, which houses the two duo valves, left/right and the coolant circulation pump for the heater. If you need to know of its location, then it’s just to the right and slightly rear of the brake servo unit under the plastic scuttle panel. To be honest with you Ray, from my own personal experience, most people are frightened to death of going anywhere near a W215 for obvious reasons, and those that are brave enough to do so have to tread very carefully as it is so very easy to cause additional damage. Noting from the lack of input to this thread says it all really; it’s probably why no one on here has offered to help you other than to guess at what it might be. If you do get someone skilled enough with a STAR machine, then it’s very easy for them to go in to the system and then check the entire individual sensing/active components.

    I’m off work now until Tuesday, but I will come on to the forum sometime over the holiday period to see if you have resolved the issue, if you haven’t, then I’ll explain what to do and how to go about it. Its not difficult, but you will have to be able to navigate where to go and what to check, some of these modules require a considerable amount of interior trim to be removed to gain access, we can also assess them in isolation so you will get a better chance of finding the right culprit. As laborious and time consuming as it may be, (without the aid of diagnostic equipment) it’s the only way to do it properly. Some modules actually do go to sleep and then have a tendency to awaken again, but that’s another matter and way beyond the scope of this thread, so you will have to be patient and monitor the meter readings for quite some time.

    My wife’s old CLK 500 (A209) model, well I say old but it was actually a 2005 model when I bought it for her in 2006 as a used vehicle from MB, what a stunning car that was, but it was an absolute electrical nightmare when it came to parasitic drains; lots of issues and module faults with that car and it was never away from the dealers whilst it was under warranty, even my old CL has had some issues in this area. Sometimes they can be relatively inexpensive repairs (hopefully yours is a minor issue) and the worst-case scenario they could cost you several hundreds if not thousands of pounds. No point as I said earlier though in speculating at this juncture as to what it may or may not be – you don’t guess at what things it may be on a Mercedes Benz CL, its far too costly, so do it properly and diagnose the issue and then decide where you want go from there.

    The in-line fuse ammeter you have just bought, what is the threshold limit, is it 20 amps, if it is 20 amps, then you can use that in series with the battery although you may have to make a couple of small fly leads to connect to the battery and the battery leads. These are not the most accurate meter on the market to use but it will give you a rough ball park figure as to what current is actually being drawn, alternatively, get yourself a relatively inexpensive digital multimeter (always handy to have one anyway) that goes up to the 10 amp range. As a general rule of thumb anyway, most digital multimeters these days only go up to 10 amps and it is often the case that the fuse in the meter will blow if this threshold is exceeded, but you can initially overcome that by inserting a small switched (by-pass) jump lead first in to the system before you connect the ammeter.

    If you haven’t yet resolved the issue, then just post up on the thread what information you have and done to date and don’t touch anything else, not unless that is someone else on here wishes to volunteer and guide you through the process, anyway, speak to you sometime over the next few days to see how you are getting on. I have just read your PM’s Ray, I will reply to them when I have a little bit more time. If you haven’t got a proper fuse chart for the CL, then let me know and I will let you have a copy of my own version that I made many years ago, it still applies to the CL65 as all the W215’s are all the same electrical architecture anyway.

    Best Regards.

    [FONT=&quot]Dash1[/FONT]
     
    Last edited: May 23, 2015
    5 people like this.
  13. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Dash1 As ever thanks for the very comprehensive and detailed post on this issue. To be honest I never really got the time to have a look at this any further. I will check the acc for fault codes in the first instance as you have said. One thing I did notice is that I left the two fuses that I previously noted as drawing the power out and the battery still went flat so I am thinking that there is also something else draining the power also. Thanks again and hope you are keeping well.

    Edit: I did the diagnosis procedure for the acc as noted by Dash1 and the following code came up

    DIAGN. KLA V ERROR 1257
     
    Last edited: May 24, 2015
  14. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    I actually have an ammeter so I will have a go at linking this up in a series a see the combined amount which is drawing
     
  15. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Ok so I escaped from the house for a while and hooked the multi meter up in series and got the following after leaving if for approx 25mins image-2703841804.jpg So if I am reading the meter right this is giving about 22.7 milli amps. So a bit puzzled now as that is quite a low draw? Looks like I will have to monitor it for a while and see if it changes. When I was setting up the multimeter I noticed that the lights in the boot never went off even when I locked the car - but not sure if they always stay on if the boot is open as standard - so I just removed the bulbs to be sure they didn't draw.
     
    Last edited: May 24, 2015
  16. Dash1

    Dash1 Hardcore MB Enthusiast

    Messages:
    228
    Joined:
    Nov 9, 2010
    Location:
    Merseyside/Staffordshire
    Car:
    2013-Audi A8L (W12) Exclusive (D4) 1998 H-D FLHTCUi and FLSTS 95th Anniversary Models.
    Hello Ray,

    Thanks for the update and sorry for the late reply. Lets specifically deal with the error code first before we think of going anywhere else at the moment with the parasitic drain. By all means, carry on and use your ammeter and let me know what the final readings are, we can then go from there after we resolve the AC fault code issue.

    The error code 1257 is in fact and relates to the refrigerant pressure within the AC system and if it’s at zero or below 1.75 bar, (approx 27 psi) then the AC compressor will fail to operate and is switched off. This can mean one of three things, the system pressure sensor itself is at fault, the system needs to be re-gassed or the pressure relief valve in the compressor itself has failed. The latter is designed as a pressure dependent wax valve and it only begins to act if all other pressure-dependent safety devices have failed and can no longer support a pressure increase in the compressor and its specifically designed this way to protect the refrigerant circuit against damage - resulting from excessive pressure.

    The wax valve itself can withstand a significantly high pressure of up to 35 bar, (approx 525 psi) however, if the pressure increases beyond this threshold, then the wax material is totally destroyed and the pressure is released to the atmosphere, and hence, a possible fault code being recorded and logged in the ACC module as being very low or zero bar. The pressure relief valve itself is actually located at the rear of the compressor unit on the right hand side as viewed from the front. To be honest, it’s very unlikely to be this component that has failed and I would therefore concentrate on the other two, which are both directly related to one another.

    How is the climate control system performing, have you noticed anything untoward, i.e., not functioning or blowing cold air etc., or even the compressor not running. The refrigerant pressure sensor itself is actually located on the receiver/drier which is found under the bonnet in the engine bay at the n/side and is directly “hard” wired in to the n/side front SAM (signal acquisition module) and the data from the sensor is sent over the CAN bus to the ACC control module. The data of the pressure within the system is compared with a stored temperature/pressure graph curve within the ACC module and the system will only function in that operating region only. If you look behind the n/side headlamp unit its just below the ABS module and to the right of the PAS reservoir. It’s a 3-way electrical connector – supply voltage, ground and sensing wire, so you can’t really miss it or confuse it with anything else; right next door to it is the temperature sensor, which records the temperature in the system. We can look at the input/output voltages of the pressure sensor and its parameters at a later time if we need to go that far Ray, but it may just be out of refrigerant - when was it last checked and serviced.

    On the CL’s, and as I stated above, the system is so designed as to switch the AC compressor off if the systems pressure values are below 1.75 bar and above 30 bar, also, and in addition to that, the electric fans would be switched full on if the system pressure was above 20 bar and off if below 12 bar. Have you noticed if the fans have been running as they will work between the pressures of between 12 bars up to 20 bars and will therefore increase linearly between its minimum output of 40% and up to its maximum of 100%.


    That’s a bit extreme Ray removing the bulbs, you should have just got a small bladed screwdriver and pushed the boot catch locking mechanism up in to the second latched position, the lights would have then gone out. To release the locking mechanism from its latched position would require that you insert the bladed key in the lock and rotate it anti-clockwise until it stops and then press the lock in to release the catch. There is a 10-minute time delay on the boot lamps, which is switched off by the rear SAM control module, never mind, you will remember that for the next time.

    When you select the ammeter range, always put it on the 10 amp range scale first and you can always move it in scaled increments if required for finer clarity and precision. I can’t really make out from the photo as its far too glossy on the right hand side, but it looks like the 10 amp scale would be next to it which will shift the decimal point one place to the left. If you look back at your first post, you indicated that on the one single circuit it was showing 1.26 amps current draw, that hasn’t gone away that Ray and that equates to 1,260 milliamps which is far in excess of the scale that you are on at the moment. The reading that you now have is actually 2.27 amps or 2,270 milliamps – the original figure of 1.26 amps plus the additional parasitic drain now measured in series with the battery and the battery earth lead. If you want to prove it out, then insert the in-line ammeter that you bought back in place of fuse 82 and then carry on with your multimeter tests and insert that in series with the battery. This is potentially a very serious drain this Ray if you have carried out the tests properly, so I’ll do my best to come on the forum sometime tomorrow afternoon to see if you have updated the thread with any further data or info. After tomorrow though it will be next weekend before I can come back on the forum again as I am back at work on Tuesday.

    Best Regards,

    Dash1
     
    6 people like this.
  17. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Dash1

    Thanks for this again appreciated as I know how busy you can be. I have to say that all this information you have provided so far will no doubt help myself and many other people on the forum like me who would not be too sharp on electrical skills and in particular the complex nature of the CL's. I think you are a credit to the forum and what forums are all about really.

    A bit of background I should maybe have given at the start. When I first noticed the battery drain I did a bit of trawling the net and found one of the common causes on all types of Mercedes of this age was the alarm siren itself going faulty and draining the battery. When I checked mine was not working so I replaced it with a new one and the alarm worked again..........but obviously as I have found out this never solved the problem with battery drain.

    I have gone out and checked the AC and noticed that the AC off button light stays on even when I try to switch it off. Regarding servicing I had the car serviced just under 2 years ago with MB but I don't think they did anything with this system. I am planning to get the car serviced in the next 3 weeks with MB even though I have only put ~1500miles or so on it in that period. So may the best place to start is to get MB to check the refrigerant levels in the first instance and go from there.


    Yes extreme as right! I maybe should have been a bit smarter and did the process you note but at least I will know for the next time.

    Yes you are correct to the right hand side is the 10 amp scale. I have done a quick check again this morning and I am getting the same reading.....but I will monitor this over the next few days until the weekend. One thing I did notice as I have been in and out of the car a good bit over the last few days is that when I close the doors the rear back windows don't fully close maybe down about 5mm - previously upon closing the doors the rear panels returned to the fully close position. Not sure if this is in anyway related to the battery issue though.

    If I notice anything else I will update the thread the problem I have is actually getting the time to get at the car to do all the checking.

    Thanks again.
     
  18. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Just a brief update. I left the multimeter on for a good while today and the drain remained around 2.24amps with every now and again this dropping to 0.6amp and 1.2amp and then back up to 2.24amps. When I had the multimeter linked up I put the blade meter in fuse 82 and left the car for 30mins. When I went back it was reading -0.02amp and stayed at that without changing for hours - this is the fuse which showed 1.2 amps previously. I am thinking the best thing to do is get a few hours some day and start checking each fuse again with the multimeter hooked up in series just to be certain of any fuses drawing power when the car should be sleeping.
     
  19. Dash1

    Dash1 Hardcore MB Enthusiast

    Messages:
    228
    Joined:
    Nov 9, 2010
    Location:
    Merseyside/Staffordshire
    Car:
    2013-Audi A8L (W12) Exclusive (D4) 1998 H-D FLHTCUi and FLSTS 95th Anniversary Models.
    Hello Ray,

    Thanks for the update and the additional information, much appreciated. As I said on a previous occasion, it’s surprising what difference a little bit more information can make as I can only advise/help someone if I know exactly what the symptoms are and as they are described to me, something that I learned very early on when I used to be a mechanic, and that was a very very long time ago now before I ever became an engineer. Yes, the alarm systems are noted as being an issue throughout the whole of the MB range of vehicles, especially on aged vehicles around 8 years old or so, my old CL unfortunately was a casualty here. The NiMH batteries in the unit itself deteriorate over time and in the process damage the PCB and internal circuitry. The parasitic drain on your car therefore seems to have been a long-standing issue then, and well before the alarm was replaced.

    The light on the AAC instruments panel if illuminated is a clear indication anyway that the system has developed a fault and is therefore shutdown to prevent further damage to the compressor and its associated components. How long has this light been on Ray, a week, a month or has it only just come on whilst carrying out your checks and tests. Have you tried to clear the fault codes as I described earlier, if you have and the fault code returns then it’s a clear indication anyway that there is a “hard” fault within the system. As you say though, it is well worth getting the refrigeration pressures checked and the system re-charged if the vehicle is going in to MB shortly for a service.

    Please let me know what the outcome is and prior to you having it repaired and I will see if they are giving you the right information. From what I have noted, it’s down to two specific area issues here, the pressure sensor itself or a system pressure loss. Is that the only fault code that was logged in the AAC control module, did you try and scroll through the menu to see if any others were present. If need be, then I can guide you through the electrical diagnostics so we can determine if the AAC module is supplying the sensor with its reference and return voltages.

    When you set up the multimeter prior to doing the ammeter tests, the meters leads were in fact in the correct place as to measure in the 10 amp scale division only, however, the selector switch position that you chose was actually on the 200m scale division, which was incorrect and therefore I think this is what was confusing and misleading you in to thinking that it was only drawing 22.7 milliamps, this is not possible Ray on a car like the CL65 and I am expecting a figure of up to and around the maximum threshold of 0.047 amps, depending upon what is actually fitted to your car. Anyway it now looks like you have got the hang of using the multimeter gauging from you last post.

    The correct way to measure parasitic drain on your car would be to make sure that everything is turned off, the bonnet is down, both doors are closed, the boot lid is open and the boot catch locking mechanism is closed and secured in the second latched position. The rear SAM control module recognises the microswitch is closed in the boot lock mechanism for the alarm system to be fully activated. We only want to monitor it at this stage Ray, so don’t at the moment try to find the drain by removing fuses etc. When you come to do the test, disconnect the negative battery lead and insert your ammeter, wait for it to settle down and then press the remote key fob so that the vehicle is “globally” locked and the alarm is now armed. Now wait for the modules to shut down and go in to “sleep” mode. Monitor this process over the next hour or so if you have the time and keep checking if there is any noticeable difference, if its possible, then let me have the results for next weekend and we can go from there.

    Ray, to put your mind at rest, there is no direct relationship or link here with the window issues with regards to you current fault issues, however, the AAC control module does in fact communicate over the CAN bus with various other modules on the car to establish the correct climatic condition inside the cabin, that includes as to whether or not the windows are open, sunroof open etc, again, very complex as I previously explained and once again way beyond the scope of this thread. If I do think that it’s relevant to our issue, then I will cover and go over it.

    The issue with the rear windows being lower by 5 mm is probably one of just requiring re-synchronisation. Did you reset the windows; sunroof and ESP after disconnecting the battery, if not, then these will in fact need doing. With the ignition switched to the “on” position and from the drivers door switch pack, lower the o/side front window and at the same time keep holding the switch down until it reaches the bottom, hold it there for a minimum of 10 seconds and release the switch, from here, do exactly the same when raising the window and hold it in the closed position for another 10 seconds. Do this procedure on all the windows from the driver’s door switch pack and exactly the same procedure on the sunroof with the switch in the overhead console. Finally, turn the steering wheel in the anticlockwise direction to it stop position and then fully clockwise and back again to the straight-ahead position - everything should now be calibrated and synchronised.

    From the above, this is how the front and rear windows actually function if synchronisation fails to correct the 5 mm short stroke function. There are two contact switches (one either side) located just underneath the door locking striker plates. When the doors are either opened/closed, this information is received and read in by the rear SAM control module. The rear SAM control module sends this information over the data bus (CAN) to the rear control module, this rear control module is responsible for the rear window operation and functionality of several other things on the car, this module then sends a further message over the CAN bus to both the n/side and o/side front door control modules.

    All these modules, front and rear are responsible for the opening/closing of the windows and to retain any calibration data within the memory during operation. They are also responsible for the 5 mm short stroke function, which ensures that the doors and the frameless side window glass can be opened and closed with sufficient clearance to eliminate the glass catching/fouling the weather seal. From the initial moment that the door is opened, you will probably note that the glass drops down approx 5 mm; this is to gain clearance from the upper door/roof seal. When the battery is disconnected, they all lose their short-term memory as to what the previous positions were prior to any power losses, i.e., the battery disconnection prior to you doing the parasitic tests or previously changing the battery. There is quite a lot more to it than that Ray, but for now I will sign off the thread until next weekend. It will probably be on Sunday as I will be busy on Saturday anyway. If you do obtain any additional information, then please post it on the thread.

    Best Regards,

    Dash1
     
    Last edited: May 25, 2015
  20. OP
    OP
    rk100

    rk100 Hardcore MB Enthusiast

    Messages:
    538
    Joined:
    Sep 2, 2012
    Car:
    W215 CL65 AMG & W124 E500
    Thanks Dash1

    I will digest your post in detail and come back on at the weekend with my findings.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.