1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

C240 (W203 2001) Central Locking problem

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by grahamwoodward, Mar 6, 2011.

  1. grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Hi

    Apologies if I've added to other threads along the same lines, but car is driving me mad.

    My 2001 C240 (W203 elegance auto saloon) has developed a fault with the central locking. It won't lock from a distance. Changed the batteries in both fobs. Still doesn't work, sometimes even when only a few inches from the door handle sensor. Somedays it will; others it won't.

    When locked with the fob (sometimes) but opened with the key, alarm does not go off, but hazards flash. Is this right? The door lock button on the dash works as does the auto lock after 10mph. Also, correctly, unlocks all doors when a door is opened from inside.

    Someone said it might be the amp in the C pillar - anyone else have any thoughts before I start to tear out the trim and spend money? MB dealer quotes £107 plus vat just to diagnose! Other garages don't want to know.
     
  2. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    Yes if it works with the key a few inches from the door handle but not from way off the Amp in C pillar will have failed, this normally affects the radio where reception will be poor and noisy.

    The key could have failed on the RF side, is the spare the same
     
  3. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Hi

    I don't have any radio reception problems, and both key fobs are the same. Today (Sunday) it would not lock or unlock with the remote fob at all - I had to use the metal key. How do you test the key fobs?
     
  4. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    23
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    check the fuses in the rear sam, it is possible the siren is faulty and has blown a fuse which will give you this issue - possibly fuse 7 or 8 but not sure. the radio reception will be affected on the AM wave bands if this is the case.
     
  5. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    In front of a digital camera
     

    Attached Files:

  6. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    The amp also have 2 smd fuses in side that can be replaced
     
  7. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Thanks guys.

    Tested the fobs with my digi camera - they're working OK. Fuses haven't blown - fuses 8,9 & 41 for alarm also control (amongst other things) interior central locking switch (which still works), convenience locking (which still works) and boot release (which still works).

    AM radio reception is fine (if you can ever say that about Medium-wave). Looks like it could be more serious than the amp/antenna although could be the fuses as 'television' says. Hope so.

    Car is going to local garage tomorrow (Tue 8th) who says he has a Merc himself and that his mechanic is MB trained (why isn't he still working for MB I ask myself?). Labour charge to diagnose is £57 per hr instead of £107 at MB agents.

    Will let you know the outcome.

    Thanks again.
     
  8. horgantrevor

    horgantrevor Senior Member

    Messages:
    1,576
    Likes Received:
    0
    Joined:
    Feb 13, 2008
    Your Mercedes:
    E220 CDI avantgarde c43//amg
    keep us posted good luck
     
  9. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    Does the guy have STAR
     
  10. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Don't know about STAR, but the garage rang this morning to say that the fault is with the door handle. Apparently after testing the system and speaking to MB it seems that the sensor circuit in the door handle is not processing the signal from the amp/receiver, which is why sometimes the key fob works next to the door and other times it doesn't.

    They quoted £30 plus vat for the replacement door handle, plus painting (apparently they come in primer coat only) and fitting. They also said it may need re-programming afterwards. Might not be as bad financially as I expected.

    I will re-post when fixed. Thanks again everyone.
     
  11. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    The door handle has nothing to do with the long range locking, the could should lock from 25 feet or more
     
  12. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    W203 Central Locking C240 (2001)

    :mad:Update - central locking fault C240 W203 2001 Y reg.

    Diagnostic system reported a fault with the door sensor (driver's door). Obtained a new door lock assembly (from MB in Germany - came pre-programmed) - central locking now works everytime, BUT only from the driver's side of the car, which implies that there is another fault somewhere - the amp most likely. However, I don't have any radio reception problems, even on AM which I never use otherwise.

    At least I can now centrally lock the car, but the garage told me to take the car back to Merc to diagnose for second fault. At £107 plus vat per hr its starting to get expensive. I had three Vauxhalls (Cavalier and two Vectras) beforehand, over a 15 year, 150,000 mile period and never once even replaced the batteries in the keys! What with the rust on the back wheel arches, two faulty seat controllers and now the central locking, I'm beginning to lose faith in Mercs.

    So, question please: do I have to remove the rear seat to get to the amp to check its fuses? Or, should I just go to the merc garage and hope my credit card is really flexible? What's the consensus?
     
  13. rpe2

    rpe2 Senior Member

    Messages:
    2,856
    Likes Received:
    1
    Joined:
    Sep 25, 2006
    Location:
    Silchester
    Your Mercedes:
    His: 2010 E350 CDI; Hers: 2011 XC90
    You could find an independent in your area at half the price.
     
  14. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Central locking C240 (W203)

    Update on C240 central locking and other probs - after 2 months since replacing the door (keyfob) sensor, central locking works but not from any distance. So, amp appears to be the problem as I am now having radio reception problems. Also, alarm siren doesn't work.

    Also, despite my earlier blog, pulling fuses 1 & 2 in the boot did not stop the seat control units draining the battery. Had to also pull the fuses in the dash. That stops the battery being flat, but the seats don't move.

    Is anyone able to fix both the problems for me if I drive to their location? Can anyone rewire the seat controllers for me and mend the amp? I will travel anywhere (in reason). No point in having a lux car if half the electrics don't work. Can't pay Merc dealer prices but will pay fair cost of repairs. Pleeeease.
     
  15. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Central locking - part2

    Part 2

    Fuse 8 in the boot has blown - which is perhaps why the alarm siren doesn't work. Just replaced the fuse and it blew immediately. Great eh. What's all that about then?
     
  16. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    23
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    there you go, usually the siren blowing the fuse.
     
  17. OP
    grahamwoodward

    grahamwoodward Senior Member

    Messages:
    134
    Likes Received:
    15
    Joined:
    May 9, 2010
    Location:
    Midlands
    Your Mercedes:
    W211 E320 (petrol) Avantgarde Saloon (2004); R170 SLK200 Komp facelift-model (2001)
    Hi Alex - I never doubted your diagnostic ability. So, are you saying that the faulty siren is causing the problem with the remote central locking in that it's stopping the amp from picking up the key signal?
     
  18. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    The amps can go short circuit, we have had quite a few on here
     
  19. Alex Crow

    Alex Crow Senior Member

    Messages:
    10,677
    Likes Received:
    23
    Joined:
    Jul 9, 2009
    Location:
    Super Suffolk
    Your Mercedes:
    W169, W124, w202, W203, KTM 250 EXC, VW T25 camper and a Polo in a pear tree
    that is what i am suggesting, although it could also be the aerial amplifier (as suggested by others), or the inclination sensor (far less likely).

    it is odd though that the fuse was initially OK, and that your radio reception was OK.

    i would be tempted to disconnect the siren and try a new fuse if i were you - the alarm will be fine with the siren disconnected. it is located in the passenger side front wheel arch, right at the back low down where the floor pan meets it. if fuse still blowing you can disconnect the inclination sensor mounted above the rear sam, if still blowing then the amplifier is next.
     
  20. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    270
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    If you need to unplug the amp it is in C pillar and I can give you the instructions
     
    shortdogg31 likes this.

Share This Page