Results 1 to 19 of 19

Thread: ZKE / GM3 / Body control module diagnosis

  1. #1
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL

    ZKE / GM3 / Body control module diagnosis

    I just purchased a '95 750il. Wipers and headlight washers didn't work, so I went around to pulling the E-box apart and getting to the relays to test those. They turned out fine, and I bypassed the first relay for the wipers which made the system function. At that point I thought it was either the stalk itself, or eventually got around to figuring it was the GM3. When I finished putting the car back together, everything else associated with the GM failed. Interiors lights, soft close trunk, rear window controls, wipers still, and central locking.

    I'm not sure if I killed the module by messing with those relays, because it'd be ridiculous if it was that sensitive, but I could understand that.

    Today I went to my local junker and got 2x ofd the same GM3 out of two 528i E39s. Both white instead of the black that came out of my E38. Both "low." Both didn't fix anything once I plugged them in. Instead, they just made my soft close motor in the trunk continually run. Central locking, windows, etc. was all still broken.

    Did I grab a GM that was incompatible with my vehicle? or is my failure somewhere else? Also, is it possible for just a couple of functions of the GM to fail? Like only wipers and headlight washers? or does it all go at once?

  2. #2
    Join Date
    Dec 2015
    Location
    DMV
    Posts
    437
    My Cars
    00 BMW 750
    i know that all E38's used the high GM, so if you got a low, that is the incorrect module for the car.

  3. #3
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    It was my understanding that it didn't matter if it was a "low." I just thought it lacked just a few features but would still function.

  4. #4
    Join Date
    Apr 2014
    Location
    PA
    Posts
    1,522
    My Cars
    1992 525
    Did you check fuses at all? I had similar issues and a fuse in the trunk was blown. I forget what it was listed as.
    "Helicopters: 10,0000 pieces of metal fatigue rotating around an oil leak."


  5. #5
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    I'll double-check the trunk. Isn't there also fuses under the rear seat?

  6. #6
    Join Date
    Feb 2009
    Location
    KC North, MO, USA
    Posts
    11,153
    My Cars
    1996 740iL
    Main fuse block under the passenger front. General Modules, although being a '95 it maybe a Check Control Module, rarely just go bad all at once.

  7. #7
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Say again?
    And trunk fuses are fine.

  8. #8
    Join Date
    Dec 2015
    Location
    DMV
    Posts
    437
    My Cars
    00 BMW 750
    there is a fuse box under the passenger carpet, if water gets in, it can wreck havoc

  9. #9
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Quote Originally Posted by tjpike View Post
    there is a fuse box under the passenger carpet, if water gets in, it can wreck havoc
    Is it at all related to the GM and is it a pain to reach?

  10. #10
    Join Date
    Feb 2009
    Location
    KC North, MO, USA
    Posts
    11,153
    My Cars
    1996 740iL
    Just thinking out loud. The Light Control Module was two different modules in the '95 model. I don't think either would be involved here. The fuse block under the front passenger seat powers many of the fuses in the ebox. It often gets wet when the sunroof drains get clogged.

    Realoem doesn't show any GM's compatible outside of the E38 models.

  11. #11
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    F-word. Guess I'll have to scrounge around for one somewhere.

    I don't see why one of those fuses would've failed while I was diagnosing the car. Guess I'll check those too.

  12. #12
    Join Date
    Feb 2009
    Location
    KC North, MO, USA
    Posts
    11,153
    My Cars
    1996 740iL
    That would be odd. Water under the seat usually shows up slowly with odd electrical issues. The wiper issue is often the connector the relay plugs in to. The drain in the ebox gets clogged and water corrodes the bottom of those connections. You have to physically pull them up to look at the bottom of them.

  13. #13
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    I had checked, and compared to photos from others, I had minimal corrosion. I did pull each of the five relays, however, with the battery still attached. Along with all of those plugs just left of the three computers that I removed too.

  14. #14
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Just got a high unit out of a 99' 740 from local junker. Gonna give that a try.

  15. #15
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Same deal here. Plugged in the new GM, and the trunk motor continually runs, and nothing that’s supposed to work does.

  16. #16
    Join Date
    Feb 2010
    Location
    Hampshire UK
    Posts
    8,872
    My Cars
    99 840ci Sport Indv
    Sounds like you have popped Fuse 55 - that serves the GM and the interior lights....
    Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i


    My BMW Repair YouTube Channel
    My Current 840ci Sport Individual
    My Current 650ci Sport Individual
    My E31 Repair and Information Website
    My E38 Repair and Information Website
    My E63/E64 Repair and Information Website

    Chase - Heroes to a generation

  17. #17
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Quote Originally Posted by Timm View Post
    Sounds like you have popped Fuse 55 - that serves the GM and the interior lights....
    Okay. Thank you for this. I thought I had checked this properly. I hadn't. Most of the car's functions are back, though the wipers still don't work with the new GM3.

  18. #18
    Join Date
    Feb 2010
    Location
    Hampshire UK
    Posts
    8,872
    My Cars
    99 840ci Sport Indv
    Have the washers started working?

    Usual problem with wipers are the relays - and the connections under them - the Ebox can fill with water and corrode the relay base, and then the relay as the water level rises....
    Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i


    My BMW Repair YouTube Channel
    My Current 840ci Sport Individual
    My Current 650ci Sport Individual
    My E31 Repair and Information Website
    My E38 Repair and Information Website
    My E63/E64 Repair and Information Website

    Chase - Heroes to a generation

  19. #19
    Join Date
    Jan 2013
    Location
    Sarasota, FL
    Posts
    566
    My Cars
    2x 93' E34T + 95' 750iL
    Quote Originally Posted by Timm View Post
    Have the washers started working?

    Usual problem with wipers are the relays - and the connections under them - the Ebox can fill with water and corrode the relay base, and then the relay as the water level rises....
    That's exactly what it was. I went over everything once more, and wires that had appeared to be connected actually weren't. I removed the plastic relay housings and rewired what was necessary. It all functions now.

    Thanks guys!

    Now onto the windows and speakers!

Similar Threads

  1. Body control module/zke issue?
    By Eurotrash98 in forum 1991 - 1999 (E36)
    Replies: 24
    Last Post: 08-04-2022, 11:59 PM
  2. ZKE/Body Control Module question
    By 15degreeGTI in forum 1991 - 1999 (E36)
    Replies: 0
    Last Post: 09-21-2013, 04:41 PM
  3. gm3 aka body control module faults-replaced but still not working
    By krautcars in forum 1999+ X5, X6 (E53, E70, E71, F15, F16, G05, G06)
    Replies: 1
    Last Post: 03-29-2012, 04:18 AM
  4. Please Help Me, Body Control Module
    By 318matt in forum 1991 - 1999 (E36)
    Replies: 0
    Last Post: 01-22-2008, 07:12 PM
  5. Replies: 9
    Last Post: 06-22-2006, 03:02 PM

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
  •