BMW E36 Blog

BMW On Board Computer (OBC) secrets!

31st March 2007

BMW On Board Computer (OBC) secrets!

posted in Interior, Technical Info, Tips & Tricks |

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Hi Friends,


I’m really excited about this new article and I think you will be excited too. I have found an article which describes the secrets hidden inside BMW E36 on board computer (OBC). It’s really fascinating me that the Germans in 1993 or so were having such things. All I can say is WOW!. OK, enough talking about the Germans, so Mr. OBC here turned to be not as simple as I really thought at first. It has many information that is hidden and can be displayed with tiny effort. I’m almost sure that you’re going to love the article below. I just wanted to say that you should make sure to try the Instrument Panel Tests. It’s really cool to watch your car checking itself.




Note: I did try almost all what’s written in here and it’s working great.



Disclaimer: Use this info at your own risk!! I’m not responsible for your mistakes man! 😀


There are many interesting functions available on the E36 OBC (On Board Computer) that are not documented in the owner’s manual, including changing the language of the display. The procedures described here work on my ’97 328iC, which has the upgraded OBC – they may work on other models of similar vintage.



  • Programming the Display Order

  • Accessing Data

  • Unlock the Display

  • Test Codes

  • Setting the Country Code

  • Instrument Panel Tests


Programming the OBC to Display Contents in a Desired Order:


When you repeatedly press in on the turn signal stalk, the OBC display cycles through the various information types that it has in memory. The default sequence is: CONSUM1, CONSUM2, EXT. TEMP, SPEED, LIMIT, DIST and TIMER. If you want to change the display order, use the following procedure:
Press-in and hold the turn stalk for about 5 seconds. The OBC display will change to Prog 1. Press the button corresponding to the first function you would like to have displayed in the sequence. For example, if you would like the outside temperature to be displayed first, press the TEMP button. The display will then change to Prog2. Continue pressing the OBC buttons in the order you want, up through nine entries. You don’t have to enter all nine – if you would like the display to cycle only between TEMP and RANGE, simply enter those two items as Prog 1 and Prog 2. When finished, press the SET/RES button to store the sequence in memory.

To revert to the default order, simply press SET/RES as soon as Prog 1 is displayed.



Accessing Data in the OBC:

The OBC contains a lot of data, and displays the data in a manner determined by the country code that is stored in it. The technique to access this data is as follows:
Press the 1000 and 10 keys simultaneously. You should see Test-Nr.: appear in the display.
The table below lists the available test codes that are available. Enter a test code number, using the number keys, followed by the SET/RES key. However, to access codes other than 1, 10, 14, 19, and 21,
you have to first unlock the OBC, using the procedure described below.
Read the results.
For test numbers 10 and 11, enter a new value (if desired) and press SET/RES.
Return to the normal display functions by pressing CHECK or any other key.
Unlock the Display:

Most of the test sequences require you to first unlock the display before. Enter test code 19 using the above procedure. The display should read LOCK:ON. Then enter an unlocking code consisting of the sum of the current month plus date (for example, if today is July 11, enter 18). Then press SET/RES, and the OBC is now unlocked.

Test Codes:

Following is a listing of the available tests, along with with my notes as to what I think each test means. Note that the display uses European conventions for decimals (i.e., the number 61,7 is 61.7f or us Americans). You will see that I don’t have good explanations for several of these test codes

Test Code No.



Display Must Be Unlocked First?


All LED display elements are lit

Verify that the display is working properly



VBR: n,n l/100km

n,n = instantaneous fuel usage in liters/100 km



VBR: n,n l/h

n,n = instantaneous fuel usage in liters per hour



RW-VBR: n,n l/100

n,n = average fuel usage in liter/100 km.



RW: nnn km

nnn = range in km



Not used



TMTL: nn,n l

nn,n = fuel remaining (in liters)



V: n km/h

n = instantaneous speed in km/h



UB: nn,nn V

nn,nn = system voltage (should be
around 13,80)



LAND: n xxx *

Country code — for US drivers
should be set to 2 USA — see description below



EINHEIT n: xx *

?? There are two EINHEIT displays: the values for xx in EINHEIT 1 can range between B0 and BF, and for EINHEIT 2 range between 0F and FF (mine is set to B3 and FF, respectively). Press the 1000 or 100 key to switch between EINHEIT 1 and EINHEIT 2.



VANK nn km/h

nn = average speed



ANK: nn:nn

nn:nn = ETA (will display
if the OBC’s distance function is not in use)



ROM: = Software version date. Mine is 25.06.1991



DIAG: nn nn nnn xx

Diagnosis code? Mine is 01 05 255 FA



PORT: nn nnnnnnnn

Port codes? Press 1000
or 100 key to cycle port numbers. For example, PORT 01 is 10101000



PROM: nn nn

?? Mine reads 00 12



HORN: xxxx

(Single tone horn versus dual tone)



LOCK: xx

xx = ON or OFF.
See description above for method.



KVBR: nnnn

nnnn = Fuel rate calibration factor. Mine is set to 1000




Reset all defect codes? Also erases all stored values in the OBC (i.e, fuel consumption, avg. speed, timer, etc) and clock.



Note: #20 The factor is used to correct the OBC Avg Fuel Consumption figure to reality. If your OBC is off a bit, fill it UP totally and then run the tank down and refill. Then calculate your Actual MPG. Now enter test #20 get the old Correction Factor. NEW CF = OLD CF *(Actual MPG/OBC MPG)

Setting the Country Code:

If your OBC suddenly starts displaying every thing in German, and you would like to put it back to English, use test sequence number 10. Once you’re into test number 10, press the 1 key several times, and you’ll see the display cycle through various country options. For example, 0 is for Germany (the display reads LAND:0 D * – I assume D stands for Deutschland). As you cycle through the options, you’ll see choices for the Great Britain, USA, France, Canada, etc. Once the display is on the country you want, press the SET/RES key to store your choice into memory — for US drivers the display should be set to LAND: 2 USA * . Then press the CHECK key, and the display will reflect the units of the country you’ve chosen.

Instrument Panel Tests:

With the engine off, press and hold the trip mileage reset button, and then turn the key to accessory position 2 (OBC and radio come on). The LED display on the instrument panel (which normally is the odometer) will change to tESt01 and then will begin to cycle through several displays. Release the button. The display will continue to cycle through several displays. Here’s the data my car displays:


Display Sequence




BMW Part No.



Code No.?



K No.?



Last 5 digits of VIN



Software Version



Revision Index Hardware No.


Finally, all LED elements will light, and all gauges will cycle once.
You can press the mileage-reset button again to access more tests. Tests 2 through4 are always unlocked and hence available. Tests 5 through 14 are normally locked — to access these you must first unlock the display-using test 15.Otherwise the display simply shows: ——–.




Test Sequence




Engine type: n = 2 for 4-cylinder engine, 3 for 6-cylinder, and 4 for 8-cylinder



km traveled since last oil service reset.



Age of car, in days

For tests 5 – 13, display must first be unlocked using sequence 15.



SI evaluation factor: n = 0 or 1 (over-rev), t= 0 or 1 (engine temp over heat)



Fuel level and coolant temp. Displays hexadec codes relating to gauge position:

Fuel Gauge Hex value:
A (empty) —-> 0d
End of Reserve —-> 37
B ——> 54
C ——–> 90
D ———> c4
E (full) ——> f0

Engine Temp Hex value:
A ——-> ce
B ——–> 6d
C ——–> 5c
D (center) ——> 4f-23
E ——–> 1e
F ———> 18



Current engine RPM



Current road speed in km/h

nnnnnn A


Distance – used to compare odometer mileage in the EPROM vs. the coding plug. If the two values don’t agree (for example, if one of these elements was replaced), the manipulation dot will illuminate. This function will synchronize the two readings to the highest value. Press and hold the reset button for 4 seconds, and the lower mileage reading will be overwritten by the higher, and the manipulation dot is cancelled.



Status bits – input signal (0=low
or 1= high):
1: seat belt: fastened =0
2: ignition lock: key inserted=0
3: door contact: door open = 0
4: clock button pressed = 0
5: SI reset = 0
6: EGS transmission failure = 0



Status bits – output signals:
1: Gond output
2: Brake warning lamp
3: Low fuel warning lamp
4: EGA lamp
5: Seat belt lamp
6: manipulation dot



Not used



Country code of cluster (USA = 02)



Software reset

L On/Off


Lock Status (on or off). Press and hold the reset button for about five seconds until the display reads "OFF". Now you can access test sequences 5 through 14.


Wait for more from . . . BMW E36 Blog


Best regards,

Tony Sticks.

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There are currently 134 responses to “BMW On Board Computer (OBC) secrets!”

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  1. 1 On September 6th, 2008, Alex said:

    Hey guys, Thanks for the fantastic info. I have a 91 model 320i in Australia, and so far I have tried everything with mixed results. When I try to unlock the obc, I enter the date plus the month, but it still says lock:on. However, I can access all of the 18 button obc functions. A few questions – 1. Can the fuel consumption features be changed so that consum1 shows average fuel consumption while consum2 shows the instantaneous consumption? 2, can the speed button be changed to show the instantaneous speed instead of the average speed? 3. I can not access the features through the trip meter, it runs through the 6 numbers and then the gauges cycle, but holding or pressing the trip meter button again achieves nothing (not even the unlocked features) – Any ideas why??? 4. On my OBC, I have a button labelled “code”, when i press it displays 0000. I have no idea what this means, or does… any ideas??? Thanks very much, any help will be greatly appreciated! Alex

  2. 2 On September 7th, 2008, Alex said:

    Tony, any idea how to remove the interior light?? Mine has a horrible rattle, annoying at highway speeds as it hums from the vibrations, and I have just tried to pull it out so I can sort it out, but looked and couldnt find an obvious way to remove it out of the headlining. I didnt want to rip it out and be left with a ugly mess a foot from my eyes! Once again, any help would be greatly appreciated. Alex

  3. 3 On September 7th, 2008, Tony Sticks said:

    @Alex: Hi Alex, About changing the fuel consumption and speed buttons display, I’m not aware of any method to do that. About your trip meter question, I have the exact problem. I guess that some cars do not have this feature, only test 01.

    Now for the Code button, it’s a security feature that should prevent anyone from turning your engine on unless the security code is entered. Please refer to my post BMW E36 on board computer . . . learn how to use it for instructions on how to use this feature.

  4. 4 On September 7th, 2008, Tony Sticks said:

    @Alex: I recall that I have used a flat screwdriver to remove it. It should popup easily with some effort. But try to do it carefully.

  5. 5 On September 7th, 2008, Alex said:

    Thanks very much Tony, I thought being such an early model it may not have the other odometer functions. Ive checked out the link you gave me regarding the code button, thanks, and Ill give the interior light another look at tomorrow.
    Cheers, Alex

  6. 6 On September 9th, 2008, Tony Sticks said:

    @Alex: Good luck Alex.

  7. 7 On October 28th, 2008, Nurman said:

    Dear Tony,

    I have e36 m43, and i would like to put an on board computer in this car. cause in my car have analog clock only (poor me rite). on ebay i found multi information display 18 button for e36. Can i have this MID on my car. Just plug and play or i must face some kind hot wiring stuff…
    can i do it by myself on these project????

    thanks tony

  8. 8 On October 28th, 2008, Tony Sticks said:

    @Nurman: Well, to be honest, I didn’t try the upgrade myself. But I recall that I’ve seen some DIYs to upgrade from the 7-button to the 18-button OBC. I think it’s a little bit complicated if you don’t have electrical knowledge about cars.

  9. 9 On March 4th, 2009, rado said:

    ahoj potreboval by som zistit preco mi pocitac ukazuje na chek control INAKTIV? NEVIETE MI PORADIT?

  10. 10 On March 19th, 2009, Vusi said:

    My OBC is currently displaying Prog.1 nothing else seem to be happening except when i turn on the key, it displyas temp for 3sec then revert back to Prog. 1 what do you suggest i do?

  11. 11 On April 8th, 2009, Dayo said:

    Hi Tony, I am trying to replace my OBC as the ‘100’ button is broken. I saw a used one online for about $50. Will a used one work just fine? What do I need to watch out for? Any suggestions? I am assuming all I need to do is remove, unplug wires and replug wires into new OBC. Please advise.

  12. 12 On April 21st, 2009, rev.bess said:

    anyone know who has a ecm for a 92 bmw 325i (e36) #0 261 200 402. and also how much is 30 Euros in US dollars too thanks.

  13. 13 On April 23rd, 2009, ukfrog said:

    Ebay for the ECM
    And 30 Euros is about $40 US. In the future you can search google for “currency converter”, I don’t want to plug any sites, but they are EASY to find.

  14. 14 On April 23rd, 2009, rev.bess said:

    thanks a lot for some reason my computer started back working i opened it and replaced the dinan chip with the original it didn’t work right away but it worked the next morning???? that’s funny but thank the lord its working. anyone have a comment on this situation please post. i don’t know what the heck happened. it did this 1 time before.

  15. 15 On May 13th, 2009, howardf said:

    hi, jut found your blog and read most of it, i will try the oil reset tomorrow on my 1997 bmw 316i coupe and let you know. one thing that is on the the air bag light. i have read other blog about replacing the sensor, but where on the car would these sensor be

    great blog by the way

  16. 16 On September 6th, 2010, Niels Bang said:

    The mystery of BMW E36 ON-BOARD-CMPUTER calibration.

    I don’t know if it’s allowed for a Dane, to ask a question about BMW E36 OBC-V. I have got one of those – it came from a 6 cylinder car, and my car is a 4 cylinder.
    I can’t make it show the true consumption value for my car, and the BMW Workshop can’t re-code/re-calibrate the OBC to a 4 cylinder car.
    I have been looking the Secret Menu #11. EINHEIT 1. and 2.
    What do the values in EINHEIT 1. and 2. indicate?
    Does it have anything to do with E36 engines – 316i, 318i, 320i, 323i and so on?
    Does it indicate, that it’s possible manually calibrate the OBC for a certain engine – 4 cylinder, 6 cylinder?

    For your information I have just got a OBC-V which used to be in a 4 cylinder 318is, when I install this OBC in my car, it’s possible by adjusting Secret Menu # 20 to get the true consumption values for my car.
    The interesting thing is, that the only difference on the 2 OBC is to be found in Secret Menu # 11.
    The 6 cylinder OBC have those values: EINHEIT 1: 7D, EINHEIT 2: FF
    The 4 cylinder OBC have the following values: EINHEIT 1: 75, EINHEIT 2: FF

    As it is possible change the values in EINHEIT 1 and EINHEIT 2, I have been wondering if somebody have the code for what value refer to what engine or car model.
    As I see it, then it looks like EINHEIT 1 is the key to the configuration of the OBC – but which values mean what?

    Hope someone in the Blog can answer my question as I know a thousand or more BMW owners do have the same question.

    Look forward to hear something.
    Thanks and regards
    Niels Bang

  17. 17 On November 10th, 2010, jimmy said:

    I have a question… My DME was fried in my 1998 BMW 740IL so i got a used one from LKQ auto parts. The problem is that it needs to be reprogrammed because of some type of security issue and the mechanics say they’ve never had to do that soooo I have to figure out where to send it to get that done or HOW TO FIX IT… I live in Jax, FL… Anyone know how to reprogram this or where I could send it to get it done?

  18. 18 On November 29th, 2010, Migi said:

    Hy Neal!
    I have the same problem with my OBC. I can’t write the right number in TEST 20, so my OBC doesn’t shows the right consumption. Had you find expedient?:) Thank you!

  19. 19 On November 29th, 2010, Gep said:


    The EINHEIT1 code not change consumption value or the engine type. The EINHEIT1 value is a bitmask. Where the different bits set the different settings. For example: if first bit value 1 then the OBC clock 12 hours mode, if bit value 0 then the clock 24hour mode… ect bit1 – bit8. I could not fathom the EINHEIT2 but the value is not affected the consumption.

    Good Luck!

  20. 20 On November 30th, 2010, Migi said:

    So that was the wrong way:( Thank you!

  21. 21 On November 30th, 2010, Gep said:

    I am also looking for the cause of the error. Me calculated KVBR 511 and the minimum value is 750 in Test#20. So 8l consumption instead of the OBC writes 12l. If I know the reason of the error then I write here.


  22. 22 On February 8th, 2011, jeff said:

    Today, I popped out my OBC to switch some bulbs around so I could read the clock display. Upon reinstall it read “CODE —-“….and the code button was illuminated. I messed with it for a few minutes but could not get it to clear. I went in to work….
    10 hours later I come out, and my car won’t start. Tried jumping it off, but no difference. Then I remembered the display message. I popped the OBC out and unplugged it, and the engine started right up. Sweet I thought, then I plugged the OBC back in, and it began counting down from 15:00 (minutes)….I didn’t know if the engine would cut out or what….so I unplugged the OBC and drove all the way home without issue.
    What is “CODE —-” and what is it asking for? Part of the vin?

  23. 23 On February 16th, 2011, GuyNo1 said:

    “What is “CODE —-” and what is it asking for? Part of the vin?”

    This is a anti-theft function which can be normally set directly by the driver. It has nothing to do with the VIN.

  24. 24 On March 17th, 2011, Gep said:


    Your local Dealer can recode your OBC with the so called “Modic/DIS” – testing unit. This equippment has every BMW-Dealer.
    You basically let your car know, thats an OBC is installed and program the right car type into your obc.
    You can do it as follow:

    Let your dealer do this steps:

    Plug in the Modic – Unit into your car’s diagnostic socket.
    Select your Car-Type from the Menu.
    Then you can choose some sort of diagnostics and other things.
    One Menu Item is the so called “Electronic Retrofit”
    In this Menu you can choose all sort of Retrofitting electronics, such as OBC Unit (BC V), PDC, Power Windows, etc…)
    The Recoding may take several Minutes.
    You need to turn the ignition on and off (the testing unit will instruct you.)




  25. 25 On April 1st, 2011, H said:

    How can I reset the clock in a 1992 325i convertible. The clock is in European time and also the temperature is in Celsius not Fahrenheit. The button that you put a pen into no longer works.

  26. 26 On May 4th, 2011, Skeens said:

    Hi, I have a 96 325 and today my obc stayed on all day and killed my battery? Its never done that b4 and nothing else was on in my car. Any idea what could of caused this? Also 1 out of every 5 times i start my car my obc flashes that i have tail light failure but everytime my tail lights work. Obvisiouly a sensor? Not a big deal but annoying. Anyone else ever have these problems

  27. 27 On July 22nd, 2011, led spotlight said:


  28. 28 On September 17th, 2011, Abe said:

    Above you mention to hit the 1000 and 10 buttons simultaniously to acess data, are them buttons on the radio itself?

  29. 29 On September 23rd, 2011, Ray Montoya said:

    Hi I just bought a 1992 325is, and the module/clock was not working so i took it out and of course unplugged it, and cant seem to see why it isnt functining nothing visibly wrong, I have driven the car aprrox 75 miles without it in the car. can it be left out without harm to the vehicle? I was just reading how another guy unplugged his and then the car wouldnt start. Now I dont know what to do because if I reconnect it I wont be able to reset the code because the module isnt readable….Thanks for some help here. Ray

  30. 30 On December 26th, 2011, Cristi07 said:

    Hi all!

    Let’s assume I have a 6 cylinders OBC and I want to use it on a 4 cylinders.
    Can it be recoded/re-calibrated/re-whatever to use it in a 4 cylinders car?


  31. 31 On April 3rd, 2012, NIck said:

    I have a e32 1992 750il the dash display ie: digital , srs,brake and odmeter, fuel,tach,speedo and temp gauge are blinlinking and spiking like a flasher unit do u know what causes this please help

  32. 32 On February 20th, 2013, agence immobiliere taroudant said:

    Very nice post, Thanks for this publishing. Really help me a lot.

  33. 33 On March 28th, 2013, joeyak907 said:

    i have a 93 325i and all the numbers work on my OBC. ( :
    anybody have questions?

  34. 34 On March 28th, 2013, joeyak907 said:

    is number 15 (diagnosis code) actually a code for your car telling you wats wrong???