Results 1 to 8 of 8

Thread: Max Charging voltage, wiring diagram and general advice

  1. #1
    Join Date
    May 2016
    Location
    Maidstone
    Posts
    3

    Max Charging voltage, wiring diagram and general advice

    Hi Everyone,

    I purchased a non-running Brabus Roadster, well it runs but only at 3mph and I already love it.

    The symptoms are as follows...

    It starts, revs up to about 3,000 RPM then goes down to 1,000 -1,500 and oscillates up and down approximately every 500-800ms maybe + / - 300 RPM.

    It will go in to gear and when you press the accelerator pedal it moves off but doesn't allow the engine to rev up, only drives at tick-over.

    Someone has butchered the wiring to the SAM/ECU and replaced the Alternator with a Non-Standard one.

    Apparently it hasn't run properly since the new alternator but I think the mechanic went to town on the wiring and then gave up not thinking that he installed the wrong alternator which is NOT the standard one.
    Before I go buying another one, I want to check that it is in fact the cause of the problem.

    I also want to tidy up the wiring and make sure there are no shorted connections.

    Does anyone know the exact maximum charging voltage accepted by the SAM/ECU and does anyone have a copy of the wiring diagram or any workshop manuals?

    Could the ECU be damaged considering that the engine runs? If so, how do I go abut getting a Brabus Roadster ECU and coding it to my car?

    Also any advice would be very much appreciated

    Many thanks

    Elliot

  2. #2
    Join Date
    Apr 2013
    Location
    the Netherlands
    Posts
    206
    Maybe this guys can help?
    http://www.chequeredflaguk.co.uk/index.htm

  3. #3
    Join Date
    May 2016
    Location
    Maidstone
    Posts
    3
    Actually, it's funny you should say that because the car is currently with them. They are returning it to me Thursday un-fixed. I've been told that if they look at the wiring it could be an unknown amount of time to fix it at 40 per hour...

    Being an Electronics Engineer, I have no issues tackling the electrics of this car but I do need a map to know what is supposed to be connected to where.

    Knowing the maximum battery charge voltage right now would be handy and allow my do see if the alternator is working within the specifications of the vehicle.

  4. #4
    Join Date
    Apr 2013
    Location
    the Netherlands
    Posts
    206
    Its a shame , that they couldnt fix the problem.
    You need the correct alternator.
    With the correct connections (2 or 3 )
    I think the charge voltage 14.2 V.
    The pulse current from ECU to alternator needs to be max. 4.9 V
    This pulse starts the charge from the alternator to the battery

  5. #5
    Join Date
    Mar 2010
    Location
    Hampshire
    Posts
    1,958
    Chequered flag are worse than useless on anything other than the basics.

    You need to get a genuine alternator first & foremost - go to merc, quote your VIN and ensure they supply the correct one for your car - as there are a number of different types and you need to ensure you get the correct one.

    Beyond that, get yourself registered on www.theroadster.net as that's where you'll hook up with the Smart Roadster community.
    And there is a user on there called Stephen (goes under the name of STARBLUE) who if you need a new ECU can clone your current one onto a 2nd hand replacement so it will run.

    He and another user (Scott13) are breaking Brabus roadsters so may even have the parts you need.
    ==============================
    2004 Roadster-Coupe SB2 Brabus
    2005 ForTwo Brabus Numeric
    2014 Skoda Yeti 4x4 DSG
    ex 2002 City Coupe 600cc Pulse
    ex 2003 City Coupe 700cc Passion
    ==============================

  6. #6
    Join Date
    Oct 2013
    Location
    Swindon
    Posts
    193
    Correct alternator is Denso DAN521
    2001 Jaguar XKR 100
    2003 Roadster Coupe Bluewave Brabus SB2
    2002 Ex Fortwo Pulse


    Smart,Mercedes & Jaguar Diagnostics

  7. #7
    Join Date
    Nov 2007
    Location
    BANCHORY
    Posts
    2,983
    Engine ECU controls alternator through LIN (Local Interconnect Network), a serial network protocol. Any conventional alternator can therefore not be used.

    Edit: Having studied wiring diagrams it appears LIN is only used on the 450 Cdi, whilst petrol 450 and Roadster ECUs control alternators by pulse width modulation over PH-IN terminal.
    Last edited by tolsen; 13-05-2016 at 06:35 PM.
    Drives a Smart Cdi - 65 to 85 MPG

  8. #8
    Join Date
    May 2016
    Location
    Maidstone
    Posts
    3
    Thank you all so much for that info! I have one coming tomorrow and it's booked in for the change Monday. I'll take it from there.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •