New OBC Upgrade problems, UK E34 525i Touring

[Letimi]

Hi

I have just installed an OBC into my 96 525i Touring e34.

following instructions from http://www.bmwe34.net/e34main/upgrade/OBC.htm

I had an OBC unit from a e34 535i, along with the temp sender , and the coulomn switch (not installed yet, see below)

The basic unit works, but there are several issues that i want to try and sort, listed below, any help suggestions welcome. I can provide pics, or any info needed.

1/ MPG stays at 0.0 I can reset to --.- and as soon as I drive, it goes to 0.0 and stays there.

2/ Stalk switch. There is a 3 pin connector aswell as the main multipin, this 3 pin is the OBC switch, but there doesnt appear to be anywhere to plug it too! I have looked everywhere within reach of the loom plug.

3/ Range is way out, but if mpg isnt right, this cant be either I assume?

4/ OBC display doesnt show on the dashboard, but I do have the dash unit that shows it. I get other warnings showing, so dash display is ok.

5/ -35 deg shows on start, but I cant find the wiring loom near the radiator to fit the sensor.

All other bits work, distance, av speed, time/date, speed limit warning, which bongs in the right place too!

Thanks for reply's inadvance :)

Paul

[emw525E34]

I can't help you much but I can offer some suggestions that may help a little.
Firstly, you got way ahead of me becuase my german version Touring had only 3 wires on the green connector instead of the full compliment of 26 wires!. I need to find the rest of the wires from the dash and "drag" them to the OBC to function.
My 89 sedan had the factory OBC and it had the stalk. So, firstly, OBC reading does not show on the Console display becuase your stalk is not connected!. You need the stalk working and press it then the values on the OBC will show. So find a way to connect up the stalk.
Now, on the MPG reading which is still zero. I suspect a missing pin or wire there. got to find out which pin and test it with DVM.
This will also screw up the range numbers. How long have you ran the car on the OBC to date ?. Weeks or just days ?.

Use special codes to check you fuel tank level. Press 100 and 10 keys simultenously, you will get the "TEST" prompt, then use 1 key press until you get TEST 7 then press S/R. This will give you percentage of tank full. Should give you the correct figure. Mind you full tank show 75.6 or there abouts NOT 100%! In my sedan when it comes to 40% or 25% it matches the fuel guage display value almost exactly. This is the figure I needed from the darn OBC.

The temp wiring thats missing ?. I got the same problem there is no wiring in place. I suspect non-optioned models lack the termination wiring piece, unlike the US models which had the wiring all the way to the terminating connector. Hence, there is a bigger connector near the firewall that has 2 wire connector. The trick is to find this connector. It has eluded me for some time...

Also: I was told that the OBC part ending with 055 is the best to use.

[Letimi]

Ok, After a bit of thought / reading, I checked the conversion factor that is used to calculate the MPG, and instead of 1000, it was 0000 ...... !! Not suprised it showed 0 mpg.

I have set it to 1000 for now, and it works. Just need to do some calculations about fuel used to make it acurate.

Could anyone with a 96 525T tell me whet their conversion factor is please? just to get me nearer the correct figure.

I will be using this to calculate:


If the OBC appears to be reporting inaccurate fuel consumption figures it can be calibrated to give the correct values. - Fill the fuel tank to the maximum and reset the trip counter and one of the OBC's average fuel consumption monitors. Run the fuel tank nearly empty and fill the fuel tank again to the maximum. The amount of fuel it now takes to fill the tank is the amount used to cover the distance recorded on the trip meter so, from this, work out the actual fuel consumption of the car and then compare this to what the OBC reported as the average fuel consumption. If these two average fuel consumption figures are not exactly the same then you need to calibrate the OBC by entering a new correction factor.


The fuel consumption correction factor is a locked function of the OBC so before you can access it, you must first unlock the OBC - Access the OBC test menu by simultaneously pressing the 1000 and 10 keys so that the display changes to "TEST". With the 10 & 1 keys enter 19 on the display and then press the S/R button. Add the current day and month (as it is known to the OBC) and enter this value and then press the S/R button, the OBC should now be unlocked. To access the fuel consumption calibration factor you once more need to simultaneously press the 1000 and 10 keys so that the display changes to "TEST". With the 10 & 1 keys enter 20 (Be careful not to enter 21 as this will reset the OBC) on the display and then press the S/R button - you should now see something like 1000 CORR, this is your current correction factor. To calculate your new correction factor use the following:

new_correction_factor = old_correction_factor * actual_mpg / obc_mpg

Enter your new correction factor into the OBC using the 1000/100/10/1 keys and then press the S/R button. If you want to relock the OBC - enter function 19 again then press the C/F button to lock.

Should be fun ..



Use special codes to check you fuel tank level. Press 100 and 10 keys simultenously, you will get the "TEST" prompt, then use 1 key press until you get TEST 7 then press S/R. This will give you percentage of tank full. Should give you the correct figure. Mind you full tank show 75.6 or there abouts NOT 100%! In my sedan when it comes to 40% or 25% it matches the fuel guage display value almost exactly. This is the figure I needed from the darn OBC.
This I will check today, see what it shows



The temp wiring thats missing ?. I got the same problem there is no wiring in place. I suspect non-optioned models lack the termination wiring piece, unlike the US models which had the wiring all the way to the terminating connector. Hence, there is a bigger connector near the firewall that has 2 wire connector. The trick is to find this connector. It has eluded me for some time...

I can check on a friends car for this, has the sensor, but not the stalk, shouldnt be too hard to follow wiring back ..

Thanks for reply

paul

[Interceptor]

Use special codes to check you fuel tank level. Press 100 and 10 keys simultenously, you will get the "TEST" prompt, then use 1 key press until you get TEST 7 then press S/R. This will give you percentage of tank full. Should give you the correct figure. Mind you full tank show 75.6 or there abouts NOT 100%! In my sedan when it comes to 40% or 25% it matches the fuel guage display value almost exactly. This is the figure I needed from the darn OBC.
The fuel capacity display in the OBC is in liters not percent (at least on european cars).

[emw525E34]

Thanks. You may be right. My expereince is from my sedan which is certainly a US version and thats percent. My Euro touring still not done for OBC due to lack of full wiring harness.... will take note