BMW E36 Blog

Unlock the check button functionality for BMW E36 On Board Computer (OBC)

29th October 2007

Unlock the check button functionality for BMW E36 On Board Computer (OBC)


Hi Guys, One of the issues that were annoying me about my car is the OBC (On Board Computer) check button. Whenever I press that button, I was receiving this row of orange squares that I didn’t know what they meant. After a while, I thought this meant the car was ok and that there’s nothing wrong to report until today when I found an article that’s talking about this exact problem and how to unlock the check functionality. It turned out that the row of orange boxes (which looks like a full battery) meant that the check functionality is disabled in the car and that you have to enable it simply by following some easy steps.

Disclaimer: Use this info at your own risk!! I’m not responsible if this didn’t work for you :-).

To unlock your car’s check button functionality:

1. Hold down 1000 and 10 to get access to the hidden menus. [TEST –]

Note: please notice that this may not work if you didn’t unlock the hidden menus in your OBC using TEST 19. If you don’t know how to do this, please refer to my previous post BMW On Board Computer (OBD) secrets!.

2. Enter 11, and press Set/Reset. You will notice this on the OBC screen [EINHEIT 1: xx] (xx will be a number)
3. Change this EINHEIT 1 value to 71, using the 10 and 1 buttons, then press Set/Reset.
4. Press the 1000 button once to move to the next value which is [EINHEIT 2 xx] (xx will be a number)
5. Change this EINHEIT 2 value to FF, using the 10 and 1 buttons, then press Set/Reset.

Note: I’ve found that this value was already set correctly on my OBC.

6. After that, just press your "check" button.

I’ve tried this on my car and I have to admit it didn’t work completely as expected. Now, I receive this "Check Control Inactive" error which apparently trying to tell me that I’m one step short from making this work on my car.

Video of my car OBC after unlocking check functionality

So, if anyone can help with this, please let me know.

If your car is:
325i 1994 or 318is 1993: Set EINHEIT 1 value to 71
320i 1994: Set EINHEIT 1 value to 7B
328i 1995: Set EINHEIT 1 value to BA
M3 1997,1998: Set EINHEIT 1 value to B3

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posted in Technical Info, Tips & Tricks | 79 Comments

19th August 2007

Fixing your BMW OBC (On Board Computer) lights . . . DIY!

If you have a BMW with OBC (On Board Computer). It’s most likely that you will face a problem in its back lights sooner or later. Luckily I didn’t face this problem with my car yet, but my brothers car has this problem and his car’s OBC looks really disgusting. The problem begins when one of the back lights of the OBC decides to die and your OBC which you love to play with from time to time starts to look like a guy with black eye. At that time, you know that you have to do something about it and I know. You will be thinking … man, I shouldn’t mess with this OBC because it looks really complicated and I may end up breaking something. Guess what? you are wrong! Fixing the OBC back lights is a very simple task and it’s the subject of today’s post. I hope you enjoy this post and find it useful for your car. By the way, I want to thank Eduardo Cesconetto the original author of this great post.


For those of you who like to fix their BMW car(s) by themselves, I recommend you to get the Bentley BMW 3 series service manual which is one of the best books I’ve ever read. I got it and recommend you to get one for you as it will save you too much time and effort while fixing your car.


Disclaimer: Use this info at your own risk!! I’m not responsible if this didn’t work for you.

My OBC had only one light working, the one in the left corner, and so it was a pain to look at it, and it looked like the LCD was burned, but it comes out is just a matter of replacing some light bulbs. You can get the bulbs at the dealership for $2.50 each, and just ask for the light bulb for the OBC of your year/model car.


Here is my OBC:



The first thing to do is to carefully place a flat head screwdriver in one of the sides in the crack between the OBC and the bezel, carefully to not scratch anything, then apply a mild pressure pushing the handle of the screw driver outwards, the OBC will pop out a little bit.



Repeat the same procedure in the other side.



Under the OBC and in the top of the sunglass compartment (or whatever you want to call it) there is a hole as shown on this picture:



Put your middle finger in that hole and find the back of the OBC, then push it out slowly but firmly



That will give you enough space to pull the OBC out, slowly so you don’t pull the harness of the OBC



On the top side of the OBC, you will see the 4 light bulbs:



A bit closer…



Using the same flat head screwdriver, rotate the bulb counter-clockwise 1/4 turn to release the bulb



Install the new bulbs and follow the guide backwards to put the OBC back in place.



I suggest you replace all the 4 bulbs at once, otherwise you can end up with uneven light across the display



Are you looking for more do it yourself procedures (DIY) ? I recommend the Bentley BMW 3 series service manual for you. I got it and I think it’s a gold mine for us -BMW E36 Owners-. If you didn’t grab your copy yet, get it right now! I’m sure you’ll find this book worth every penny you’ve paid for. Get the Bentley BMW 3 series service manual


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posted in Do It Yourself, Interior, Technical Info, Tips & Tricks | 14 Comments

31st March 2007

BMW On Board Computer (OBC) secrets!

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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posted in Interior, Technical Info, Tips & Tricks | 134 Comments

20th February 2007

BMW E36 on board computer . . . learn how to use it

Hey Guys,


I’ve been looking for information about how to use the on board computer (OBC) for sometime now and I finally found it 🙂 Yaay! Below I will list what you can accomplish using the on board computer, so read on and let me know what you think.


Disclaimer: Use this procedure at your own risk!!


Outside temperature


Displays the outside temperature after pressing the TEMP (A-TEMP) button. If it falls below +3�C, a gong signal is heard as a warning; the outside temperature is displayed and flashes for eight seconds.
The warning is repeated if the temperature rises to at least +6�C and then drops again to +3�C.



Probable range


This display indicates after pressing the RANGE (REICHW) button how far the car can probably be driven on the fuel remaining in the tank. The value takes into account the way in which the car has so far been driven. A plus sign (+) in front of the displayed value means that it is still undergoing a correction process (measuring tolerance).
If three horizontal display segments flash, the range is below 15km and the car should be refuelled as soon as possible.
The on-board computer registers fuel added to the tank only when the engine has been stopped and the quantity of fuel exceeds four litres.



Average speed


Shows the average speed since the last reset. To display press the SPEED (GESCHW) button.

To reset the calculation press SET/RES. The on-board computer doesn’t include the time the car is standing with the engine off in its calculation.



Average fuel consumption


Average fuel consumption can be computed for two distances in parallel. Each time the button CONSUM (VERBR) is pressed, the display alternates between the average consumptions for distances one and two. There is also an indication of whether distance one or two is being displayed.

To reset the calculation press SET/RES.



Distance from destination


After pressing the DIST (DISTANZ) button the display shows how far the car is from the destination, provided the total distance was input before the journey started.
The probable time of arrival, which is recalculated continually as driving conditions change, is also displayed.
If the car has already completed the full distance which was input, the distance value is preceded by a minus sign ().



Speed limit


If you exceed a speed limit which you have previously input, you will hear a warning gong. The corresponding LED flashes and the display shows the stored limit briefly. The warning is repeated if the speed limit is again exceeded after the car’s speed has in the meantime dropped by at least 5 km/h below the entered value.
To cancel the speed limit input press the LIMIT button again. The LED goes out but the stored value is not lost and can be re-activated with the Limit button.
To adopt the car’s actual speed as the limit value press the LIMIT and then the SET/RES button.



Display units changeover

Press the km/mls button to switch display units between km/h and mph or litres per 100km and mpg and back.



Immobilizing vehicle


A 4-digit number can be entered with the "CODE" key in ignition switch position 1. The engine hood and radio contact is monitored when the vehicle is parked with CODE armed. The engine cannot be started until the same code number is entered again in the BC to disarm the system. Depending on the selected function, the small display shows either the date or the time. Date and time can be displayed for 8 seconds by pressing the key in ignition lock position "0".



Check control faults


A display test is performed if there are no check-control faults and the "CHECK" key is pressed for at least 10 seconds. The test appears immediately after pressing the "CHECK" key in ignition switch position 1 or when no check-control is coded in the BC V.



Arbitrary reminder


An hour signal and/or any arbitrary reminder time can be programmed or checked with the "MEMO" key:


After pressing the "MEMO" for 3 seconds enter "MEMO" appears in the large display, ":00" appears in the small display.


After entering any time (minutes) with the digit keys "1" and "10" and acknowledging with the "SET/RES" key, the hour signal then sounds 15 seconds before each full hour plus the set time in minutes.


Gong time = Full hour plus input time in minutes minus 15 seconds.


Wait for more from . . . BMW E36 Blog


Best regards,

Tony Sticks.

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posted in Technical Info, Tips & Tricks | 8 Comments

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