1998 E36 OBC+Climate Control Questions

[joryvc]

I have a 1998 BMW 328i convertible and would like to know how to change the climate control from celsius to farenheit. Also, I would like to know how to change the clock from 24hour format to 12hour format. Could someone also explain the buttons on the OBC as this car is new to me. Thanks in advance.

[Jeron]

Try holding clock till the separator dots blink to get in time-set mode, then if you have a C/F button try that or it you have a km/mls button use it. It depends on which on board computer you have.

[joryvc]

Thanks. I was able to change the clock and the date. Halfway there. Anybody know how to change the Climate Control from
Cels. to Far.?

[dfrost]

The button marked "km/mls" changes all units from "metric" to "English." Note that metric Consumption in liters/100 km is inversely related to the English miles/gallon (i.e., more of one is less of the other).

Did you know that the turn signal lever can be programmed to cycle through desired OBC displays in a user-defined sequence by pressing on the end of the lever? Method to program it is explained in the Owner's Manual.

And there are also tricks to adjust the consumption calibration using the OBC, as well as see several other parameters (at least that's true on my '93 OBD I E36). Those aren't in the Owner's Manual, but I'll explain if anyone is interested.

[Jeron]

I'm interested in calibrating by OBC mpg. Its consistently off by a couple of percent.

[dfrost]

To calibrate the indicated gas mileage:

Start by holding down the "1000" and "10" buttons simultaneously with the ignition on in any of the positions that sends power to the OBC. You'll see "TEST-NR __" on the display. If you don't see this, then the following won't work for you. I don’t think it worked for my friend’s 1992 850i.

Release 1000 and 10 buttons, then use the 10 button to enter "20" and then press the "Set/Res" button.

You should see "KVBR: 1000" displayed. That number is the calibration constant (1000 meaning 1.000).

You can now change that number with the number keypad on the left side of the OBC. For my car, I was typically reading 'high' - greater mpg indicated (let’s use 24.0 as an example) then actual (23.2 for this example). Divide the actual mpg by the indicated mpg (23.2/24.0=0.967). Use the numeric keys to scroll to 0967, then hit "Set/Res," and the display will change to "KVBR: 0967." Then either hit “Check” or turn the key off, and you’ve changed the calibration constant.

I found that it took several iterations to get the most consistently accurate value, so check indicated versus actual for several tanks and adjust the calibration constant a little – decrease the number slightly if your OBC still reads high, or increase the number if it reads low.

Here are other “OBC Test Codes” that can be displayed. For each, start by holding down the 1000 and 10 buttons, then enter the number, followed by Set/Res. You can return to the normal OBC by pressing “Check.”

1 Display test (lights up the whole display)
2 Current consumption (liters/100 km)
3 Current consumption (liters/hour)
4 Average consumption (liters/100 km)
5 Current range (km, I’d suspect)
6 Not available
7 Average fuel in tank (liters)
8 Current speed (kph)
9 System voltage at terminal R (battery voltage)
10 Country/Language
11 Units am/pm
12 Average speed (kph)
13 Estimated time of arrival (for a number entered in Distance)
14 Date of software mask
15 Production diagnosis (?)
16 Production diagnosis (?)
17 Vehicle specific data (?)
18 Alarm switch – continuous versus intermittent
19 Lock/unlock OBC (Unlock by entering date sum – good luck!)
20 Correction factor for fuel consumption
21 Reset all defect codes (does NOT reset the Service Reminder)

Too Much Information?

[joryvc]

Thank you for all of the useful information! The OBC is reading miles per gallon but the Climate Control did not change to farenheit. Was it supposed to? Did I miss something? Thanks.

[Jeron]

dfrost , thats great info thanks.

Mine is off by 1.5 mpg high on average. Thanks for the info and the example.

[dfrost]

joryvc,

I must apologise. You've been saying "Climate Control" and I've been answering about the OBC. Since I have the older non-digital Climate Control (like those knobs!), I can't help you. I presume you've searched through the Owner's Manual for clues.

[joryvc]

David, your info on the OBC was most helpful. Thank you. The owners manual makes no reference to changing the Climate Control from C to F. I'll keep looking.