BMW On-Board Computer (OBC)

[G4VHD]

As some of you may know, the BMW On-Board Computer (OBC) holds more functions than is documented, including a very nice instrument panel test. I managed to get a lot of this information from the web, but it was far from complete. Subsequently I asked my dealer for the missing info, but they could not provide the complete list either. Following is a list for the items I could find, they work in my car (E46 323i). I gather most of them also work in the E36 models. Who can tell what the missing entries represent (especially functions

9.1, 9.2 and 9.3 which are very mysterious)?

Instructions to access the hidden OBC functions:

1. Hold Trip Reset while turning ignition key to on position

2. OBC should show "Test"

3. Use Trip Reset to select function 19.0 that unlocks all the features

3. Wait for display to show "Off"

4. Depress Trip Reset for 1/4 second and release it

5. With no delay press Trip Reset several times to select one of the following function s

BMW E46 On-Board Computer (OBC) Hidden Codes

nr example description

1 Car Engine and cluster data

1.0 46nnn Chassis nr/VIN serial number (last 5 digits)

1.1 4nnn K-number

1.2 690236 Cluster Part #

1.3 045210 Coding (04)/diagnosis (52)/bus index (10)

1.4 1200 Week (12)/year of manufacture (2000)

1.5 09_160 Hardware (09) and software # (16.0) of cluster

1.6 Not used

1.7 04__44 CAN-version (04) KI-revision index (44)

2 (test) Cluster System Test - Activates the gauge drivers,

indicators and LEDs to confirm function

3 SI Data

3.0 1098 Used fuel in liters since last SI (Service Inspection)

3.1 0231 Periodic inspection days; elapsed days (since last SI)

4 Momentary Consumption

4.0 0145+ Instant fuel consumption - 0145=14.5 liters/100km

4.1 0018 Instant fuel consumption - 0018=1.8 l/Hour

5 Distance Gone Consumption

5.0 082 Average mileage; 082=8.2 liters/100km

5.1 0536 Calc. km to refuel (momentary distance to go)

6 Fuel Level sensor inputs in liters

6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters

6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters

6.2 0442+ Indicated value (44.2) and tank phase

7 Temperature and Speed

7.0 021+ Coolant/Engine temperature (2.1C)

7.1 130 Ambient/Outside temperature - chg met 5 pts. 125/130/135

7.2 + Engine speed / Current RPMs 1/min

7.3 + Vehicle speed / Current Speed in km/hour

8 Input value in HEX form

8.0 1d0+ System voltage ADC-Value Hex code

8.1 26C33C+ ADC Values HG left/HG right

8.2 0000 ADC Value brake degradation sensor (000=o.k.)

8.3 18C ADC Value outside temperature

9 Battery

9.0 140 Battery Voltage - 140 = UB 14.0v

9.1 242013+?

9.2 074_78+?

9.3 0011+?

10 Not used

11 Not used

12 Not used

13 GonG Gong Test

14 Not used

15 Status cluster I/O-ports (bit codes) 0=low; 1=high

1st-belt contact, seat belt fastened=0; 2) ignition lock contact, key inserted=0; 3) door contact, door open=0; 4) clock button pressed=0; 5) SI reset=0, for reset=0; 6) EGS transmission failure=0

Status Digital Outputs (bits) 0=inactive, 1=active

1) Gong output; 2) Brake warning lamp; 3) Low fuel warning lamp; 4) EGA lamp; 5) seat belt lamp; 6) manipulation dot

16 Not used

17 Not used

18 Not used

19 Lock Status; unlocks functions in range 3-18

19.0 L-On/L-Off Unlock: press button when "L-Off"

20 Not used

21 Software Reset; reset OBC settings

00 End of test