F355 M5:2. Fuse to accelerometer

Discussion in '348/355' started by Klas, Jul 10, 2017.

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  1. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    Which fuse is connected to the front accelerometer? It's not stated in the fuse-drawings, but I think one of the fuses for other items in the front fuse box has double jobs.
     
  2. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    Which one, Klas?

    The horizontal sensor gets its power from the Bilstein Control Unit.
    The vertical sensor gets its power from the AC System fuse (which would affect the instruments (including speedo/tacho), aircon, etc)

    Sorry, no easy solution here.

    Here's the circuit (Note that the immobiliser wiring is still to be completed)...

    1997~ 5.2 Suspension System

    Cheers,
    Ian
     
  3. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    This is the dtc I have:
    "0410 Acceleration sensor line h disconnected"

    Does it mean "h" as in horizointal?"
     
  4. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    The other possible accelerometer fault message is "acceleration sensor line L not connected", so your logic may not be valid (unless L = vertical in Italian or German).

    If you read the manual, you will see that the horizontal sensor only has two states: Open or closed circuit (no acceleration = open circuit). The Bilstein ECU probably can't distinguish between the line being open circuit and the car not accelerating.

    Have you tried any wiring checks yet? e.g. plug A pin 2 to earth (ground)? If it's closed circuit, you have a problem with the horizontal sensor (or your car is parked on a very steep hill). :D
     
  5. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    No, will do wiring checks as "disconnected" can mean bad connection i.e. oxide on a pin. (that was the fault on a door mirror when the adjusting mechanismen did not function) Also, when you stated grounding, you mean the LR coloured wire to the Bilstein A2 pin.
     
  6. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    I mean one ohmmeter probe on the blue-red pin and one ohmmeter probe to earth. If you have access to the suspension ECU in the passenger footwell, remove harness plug A, and check the resistance of pin 2 of the harness to a good, known earth. Normally you would expect infinity (unless the diagram and manual are not correct). If there is a relatively low resistance, there could be a shorted wire or faulty sensor. A few weeks ago, I could have confirmed this on my car (it was in pieces). NB: I would advise disconnecting the battery when working on the unit. There is a direct line from the battery to plug A.

    To be honest, I would suspect the vertical sensor as being faulty, but it probably has a more complex circuit inside and I wouldn't know how to check it. I seem to recall a post on the forum regarding the internals of the vertical sensor (but I can't find it).

    Unless you plan to remove the fuse/relay panel in the forward luggage compartment and start disconnecting plugs, there's probably not much more you can do (other than removing the front bumper to access the sensors).

    Anyway, please let us know how you go with the horizontal sensor wiring.

    Cheers
    Ian.
     
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  8. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    Thank's for good input. I'll let you know when I have investigated more.
    BR / Klas
     
  9. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    #8 Klas, Jul 16, 2017
    Last edited: Jul 16, 2017
    Which is A and B? The connectors are yellow and green but yellow seems to be A.
     
  10. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    Sorry, Klas, not sure. The plug with the least amount of wires is plug "A". Is this yellow?
    The "A" plug has 8 pins not used. Plug "B" only has two pins not used.

    Cheers
    Ian.
     
  11. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    Good point. Will check, but I think I'll measure in the other end at the accelerometer as I want to check the connecor status there anyhow. Can be oxide there. The connector pins are extremly tiny to the control unit.

    Also, from where comes the speed signal to the system? Maybe that one is failing as the code says "no signal"
     
  12. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    The speed signal comes in on the white-yellow wire, plug A, pin14 (from the speedometer). The engine ECU also uses this signal. I assume your speedo is working.
     
  13. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    Aha. Yes it work fine, so then is not a speed signal fault.
     
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  15. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    ..... unless the wiring from splice 30028 to the suspension ECU is faulty. If you have multiple messages and they're all associated with plug A, there may be a damaged harness.
     
  16. Klas

    Klas Karting

    Mar 17, 2014
    179
    Gothenburg, Sweden
    Full Name:
    Klas Nilsson
    Yes, can be the wiring, but I have only these 3 codes:
    0410 Acceleration sensor line h disconnected
    0408 Right rear actuator locked (works)
    0404 Left rear actuator locked (Repaired by CaptainZ)

    By that I suspect the accelerometer (vertical or horizonal?) or its connections
     
  17. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    #15 Qavion, Jul 19, 2017
    Last edited: Jul 19, 2017
    Sometimes a wiring harness runs though a firewall or bulkhead where chafing can occur. Sometimes only a few wires are affected. However, the suspension actuators use plug "B", so it's more likely that you have individual problems.

    Can you follow the harnesses. Do A & B merge for a short period, then split up again?
    Do you have a wire tracker? See this message thread:

    http://www.ferrarichat.com/forum/348-355-sponsored-bradan/525227-seatbelt-warning-light-cabling.html#post144749818

    (Edit: actually, looking at that non-related message thread, there is a photo of the suspension unit and it looks like the harnesses go in different directions.)
     
  18. Qavion

    Qavion Formula Junior

    Feb 20, 2015
    788
    Sydney
    Full Name:
    Ian Riddell
    Klass, did you confirm that plug "A" was yellow? If so, I can add this detail to the wiring diagram.

    Thanks
     

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