Results 1 to 3 of 3

Thread: E39 528i weirdness (electrical gremlins?)

  1. #1
    Join Date
    Nov 2013
    Location
    Dallas, TX
    Posts
    31
    My Cars
    91,93 525i, 2012 X5

    E39 528i weirdness (electrical gremlins?)

    Hey guys. I recently acquired a very early production 528i (6/96 production date) and it's mechanically solid with super low miles. The weird part is that there's a sticker affixed on top of the frame on the inside of the rear quarter panel (behind the trunk mounted fuse box area cover), that references a 7/97 date (using the German date format 31.07.97)). This struck me as odd because it seems to cover-up some printed information. Shows "GM" "SA" and "VN" with numbers and letters after it.

    I acquired it for cheap from a frustrated previous owner, who admittedly bought it with the same intentions as me; I can tackle this. But he's a Toyota guy so quickly wrote this off as one of those weird German cars. It has some strange issues, but when I scanned it with an Autel (one of the nicer ones) it had faults stored that were cleared and didn't come back (instrument cluster errors, airbag for passenger front, other random ones). I even scanned via the proprietary connector under the hood to scan the body modules. Here's the issues:

    - ABS, brake and traction/DSC symbol are lit-up on the dash. Autel found a few faults for the ABS module, including a valve/solenoid failure, so I replaced it with a good/tested ABS unit and all lights are still on. Also replaced the ABS sensors at all wheels. Have not bled the brake system or added fluid - got fed-up and took a break. Wondering if this needs to be cleared by the Autel and driven.

    - Transmission will not shift past second gear in drive. One time I got it to shift in to what seemed like third when I put it in to manual/sport mode, but it hasn't done it since then. I understand this is probably due to the ABS module not working properly. The transmission was replaced at some point, as the previous owner said; the pan is too clean and new to be original. Torque converter looks new too. On that note, the TCM has been opened and the EEPROM's appear to be original. I know this in and of itself could be the problem in case the software isn't compatible. But let's skip this for now and treat it like a separate thing.

    - There appears to be no power to three of the four doors but all speakers work. The only door that has power and its functions work is the passenger front door. Not even the lights for the memory seats light-up on the drivers front door. Door control modules?

    - None of the windows work from the master switch. Replaced the switch but no change. Passenger front window works from its switch.

    - Blower fan is not working - changed the FSU and no change. Fuse (red one that sits behind the glove box) appears to be good; not blown.

    - Trunk handle doesn't open the trunk, nor does the remote trunk release work.


    Changes since I've been tinkering.

    - Central locking was not working at all from the button on the console, but again only locks and unlocks the passenger front door (same thing happens when locking/unlocking from the trunk keyhole).

    - Airbag light was on, no longer is.

    For the above two items, I've pulled the fuses from the block in the glovebox and used contact cleaner to hose down the block.

    Interior lights work, headlights (and high beams) work, brake lights and reverse lights work. Sunroof works. Radio/stereo work. The car runs and drives normally save for the issues above. The motor runs smooth and purrs like an M52 should. I put a new radiator, water pump and thermostat in, because why not?

    I'm more familiar with E28's and E34's, this is my first E39 (other than an M5 I should have kept). So trying to figure out things and see if anyone has run in to this or has some solid advice about how to proceed. I have an electrician friend stopping by this weekend to do some testing with wires and things... admittedly I am not good in this area so I'll have to see what I can learn from him.

    Thanks in advance for any help you may be able to provide.

  2. #2
    JimLev's Avatar
    JimLev is offline Artifically Aspirated Moderator
    Join Date
    Oct 2006
    Location
    Sundance Mesa, NM
    Posts
    19,817
    My Cars
    00 540/6, '16 Highlander
    The FSU connector has 5 wires to it.
    2 are 12 volts and ground
    2 are wires to the blower motor
    1 is the speed control signal, the skinny wire.
    I'll have to look up which wires are which however you could see if you have 12 volts at the connector.
    I can look up the wire colors.

    Trunk problem, check fuse 53 in the trunk. If it's good the trunk actuator could be bad.

  3. #3
    Join Date
    Nov 2013
    Location
    Dallas, TX
    Posts
    31
    My Cars
    91,93 525i, 2012 X5
    Quote Originally Posted by JimLev View Post
    The FSU connector has 5 wires to it.
    2 are 12 volts and ground
    2 are wires to the blower motor
    1 is the speed control signal, the skinny wire.
    I'll have to look up which wires are which however you could see if you have 12 volts at the connector.
    I can look up the wire colors.

    Trunk problem, check fuse 53 in the trunk. If it's good the trunk actuator could be bad.

    Thank you. I will try to get in there and remove the FSU and test the wires. You know it's not a fun place to be down there...

    The trunk fuse is good so the actuator is probably toast. The rubber surrounding the handle is broken too, so water or something may have gotten in there and broke it.

    I pulled the controller for the DSC/ABS and found that one of the pins is covered in paint. Not sure if this is normal or not, but not sure if one wire/connector having a bad reading is enough to throw the whole system for a loop. Sprayed the connector and controller down with contact cleaner and will try in the morning. I'm guessing if the controller/module is bad then that might be the problem...

Similar Threads

  1. Weird electrical gremlin - failing part soon?
    By Doru in forum 1996 - 2003 (E39)
    Replies: 4
    Last Post: 06-06-2012, 12:30 PM
  2. 99 528i with electrical gremlins
    By 2 8 in forum 1996 - 2003 (E39)
    Replies: 4
    Last Post: 05-05-2012, 01:12 PM
  3. 99 528i with electrical gremlins
    By 2 8 in forum 1996 - 2003 (E39)
    Replies: 0
    Last Post: 02-19-2012, 11:35 AM
  4. 1999 528i Intermittent electrical gremlins - please help!
    By caryalon in forum 1996 - 2003 (E39)
    Replies: 5
    Last Post: 07-27-2010, 07:46 AM
  5. Weird electrical gremlin
    By olsen185 in forum Forced Induction
    Replies: 6
    Last Post: 04-26-2008, 01:16 AM

Bookmarks

Posting Permissions

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