You may need to disassemble the TCU also - there are instructions in the archives as to how to do this but its a simple matter of bending up the tabs that hold the case together and then getting at the PCB underneath.

Make sure you have an anti-static strap attached to your wrist while working on the PCB.

Once you have it removed look on the underside of the PCB - the side without the transistors etc - you will likely find that over time some of the traces have either come together particularly at posts of the relay where the relay goes through the board and is soldered on the underneath side.

get some electrical cleaner or something similar and GENTLY clean away some of the gunk aroudn the posts anywhere where it looks like it might be making a short between posts - as i said this is especially so on the relay poles.

make sure you do this with the TCU connector OFF the TCU and you only do it very very lightly.

if you foudn my other post the easiest way to check if the TRANS PROG error is being caused by the TCU is to listen very closely when you turn the ignition on. there will be a slight click when you turn the ignition to position 2 - this is the TCU self test of the TCU relay.

when you start the car, the TCU grounds the relay making it click again and stay clicked - if you can hear the TCU click again when you start the car all is well. this second click wont however happen if the TRANS PROG error appears.

between the X1537 connector wiring and cleaning the back of the PCB you will get rid of it im sure :)

750iLinOz
1989 750iL
143k, lachsilber, 17" Alpina alloys

• Still having 'TRANS PROGRAM' Problems - bmwbmwfan 2008-11-27 14:39:00 (68 views)
  • TCU diagnostics - 750ilinoz 2008-12-03 18:14:42 (24 views)
  • Do a search...I posted a detailed TCU analysis recently - 750ilinoz 2008-12-02 17:25:27 (27 views)
    • Is this the TCU connector? (pic) - bmwbmwfan 2008-12-03 12:13:53 (36 views)
    • Re: Do a search...I posted a detailed TCU analysis recently - bmwbmwfan 2008-12-03 00:03:18 (27 views)
  • Re: Still having 'TRANS PROGRAM' Problems - maun 2008-11-27 23:35:08 (44 views)
    • Re: Still having 'TRANS PROGRAM' Problems - bmwbmwfan 2008-11-28 05:29:54 (41 views)
      • Re: Still having 'TRANS PROGRAM' Problems (pic) - bmwbmwfan 2008-11-28 05:31:48 (75 views)
        • Update: Speed Sensor Faulty?? (pic) - bmwbmwfan 2008-12-22 12:17:53 (14 views)