BMW E36 Blog

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

BMW E36 Blog: The ultimate BMW E36 information source.

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.

 

Contents:

• 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	Notes	Display Must Be Unlocked First?
01	All LED display elements are lit	Verify that the display is working properly	No
02	VBR: n,n l/100km	n,n = instantaneous fuel usage in liters/100 km	Yes
03	VBR: n,n l/h	n,n = instantaneous fuel usage in liters per hour	Yes
04	RW-VBR: n,n l/100	n,n = average fuel usage in liter/100 km.	Yes
05	RW: nnn km	nnn = range in km	Yes
06	—	Not used	Yes
07	TMTL: nn,n l	nn,n = fuel remaining (in liters)	Yes
08	V: n km/h	n = instantaneous speed in km/h	Yes
09	UB: nn,nn V	nn,nn = system voltage (should be around 13,80)	Yes
10	LAND: n xxx *	Country code — for US drivers should be set to 2 USA — see description below	No
11	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.	Yes
12	VANK nn km/h	nn = average speed	Yes
13	ANK: nn:nn	nn:nn = ETA (will display –:– if the OBC’s distance function is not in use)	Yes
14	ROM: dd.mm.yy	dd.mm.yyyy = Software version date. Mine is 25.06.1991	No
15	DIAG: nn nn nnn xx	Diagnosis code? Mine is 01 05 255 FA	Yes
16	PORT: nn nnnnnnnn	Port codes? Press 1000 or 100 key to cycle port numbers. For example, PORT 01 is 10101000	Yes
17	PROM: nn nn	?? Mine reads 00 12	Yes
18	HORN: xxxx	DTON or DTOFF? (Single tone horn versus dual tone)	Yes
19	LOCK: xx	xx = ON or OFF. See description above for method.	No
20	KVBR: nnnn	nnnn = Fuel rate calibration factor. Mine is set to 1000	Yes
21	RESET?	Reset all defect codes? Also erases all stored values in the OBC (i.e, fuel consumption, avg. speed, timer, etc) and clock.	Yes

 

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	Display Sequence	Notes
363758	1	BMW Part No.
0000	2	Code No.?
7504	3	K No.?
nnnnn	4	Last 5 digits of VIN
230	5	Software Version
62	6	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: ——–.
 

 

 

Display	Test Sequence	Notes
n	02	Engine type: n = 2 for 4-cylinder engine, 3 for 6-cylinder, and 4 for 8-cylinder
nnnnnn	03	km traveled since last oil service reset.
nnnn	04	Age of car, in days
For tests 5 – 13, display must first be unlocked using sequence 15.
n	05	SI evaluation factor: n = 0 or 1 (over-rev), t= 0 or 1 (engine temp over heat)
	06	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
	07	Current engine RPM
	08	Current road speed in km/h
nnnnnn A	09	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.
bbbbbb	10	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
bbbbbb	11	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
——	12	Not used
nn	13	Country code of cluster (USA = 02)
	14	Software reset
L On/Off	15	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.

Hey Guys,

Disclaimer: Use this procedure at your own risk!!

Wait for more from . . . BMW E36 Blog

Best regards,

Tony Sticks.