13 Button OBC Tricks & Easter Eggs

[aaron325ix]

yeap, what does it do ?
on the 13 button OBC, as seen here and it reads...

30
60
CH60
CH30


__________________
Yes I want to know this too, have been for a while. I was hoping it would let me use military time but keep the Fahrenhiet/american readings.

[Magic_Black]

I have a question regarding my 13 OBC. I have an 89 325is. When i bought it I had to replace the fuse box and the cluster because both of each of them burned up, literally. The back of the SI board was burnt right underneath the tach and a few fuses burnt a section of the fuse box (not sure how, thats how I bought the car).

I replaced the fuse box with no problems. I bought a cluster from a guy who parted it out of a 91 318is. I changed the chip inside the new cluster with the chip from my original cluster and I also changed the fuel gauge from the 55 litre guage to the 60 litre guage.

My problem is that my OBC reads the 55 litres after i filled up. My car has a 62 litre tank. How do I reset it so the OBC reads correctly with the gas guage. Like the discussion earlier that the Speedo reads slower then the OBC, does the gas guage read a lower fuel reading then the OBC?

Thanks.

[atomic]

Did you swap in a different OBC unit as well? I ask as it sounds like there is a wrong code plug in it since you said you did the one in the new cluster.... Make sure the code plugs match up ?? Anyone else ??

[Magic_Black]

No, i never changed the OBC in the car.
Just the cluster

[atomic]

Sounds like the fuel gauge in your new cluster is for the 12 gallon tank instead of the 16 gallon tank. I will let you do the conversion to see if that is the deal or not. But they did have two different size fuel tanks although I am not 100% on what years and models had what.

[execuk]

Guys,
the difference between obc & speedo is only dependent on the position of the needle in speedo. btw, the obc is spot on using std wheels... this leads to...

differences between several cars going exactly at the same speed as reported is because one (or more) had non-stock wheels - example 15" rims rather than stock 14" or tires not 165/70 as this will change the geometry.

the bogttom left hole in fascia is just used to adjust the reserve. try this: when empty lite just goes on (6 lts or 1.5 gal left) adjust the pot inside hole to read that when litres are shown. this will of course alter the range calc.... btw, later usa models don't have this hole - germans may not like americans fiddling with these things :)

outstanding problems:
- what the hell is that CH30/60 rotary switch on the back?
just be aware that germans don't add stuff for nothing, there must be a valid reason! the key is perhaps what the CH stands for in german and what could be the meaning of 30/60, I can only think of secs/mins for say time to calculate or change or....
- why the litres display will never go beyond exactly 54 lts? even for later models carrying 62?
Thanks for any info

[execuk]

obc ii easter eggs

more...
- many of the things discussed in this thread will not work with sw earlier than 4.6 typ!
- there is a hidden pot inside the obc (rhs) but not accessible from outside that can do some of the fine tuning you want, sorry but can't go there myself
- the reason display flashes is to warn you about black ice at 2C, it flashes everything to ensure you are aware, classical german paranoia - that is why the liters will flash as well to force you to check the temp - very military

[Magic_Black]

Guys,
the difference between obc & speedo is only dependent on the position of the needle in speedo. btw, the obc is spot on using std wheels... this leads to...

differences between several cars going exactly at the same speed as reported is because one (or more) had non-stock wheels - example 15" rims rather than stock 14" or tires not 165/70 as this will change the geometry.

the bogttom left hole in fascia is just used to adjust the reserve. try this: when empty lite just goes on (6 lts or 1.5 gal left) adjust the pot inside hole to read that when litres are shown. this will of course alter the range calc.... btw, later usa models don't have this hole - germans may not like americans fiddling with these things :)

outstanding problems:
- what the hell is that CH30/60 rotary switch on the back?
just be aware that germans don't add stuff for nothing, there must be a valid reason! the key is perhaps what the CH stands for in german and what could be the meaning of 30/60, I can only think of secs/mins for say time to calculate or change or....
- why the litres display will never go beyond exactly 54 lts? even for later models carrying 62?
Thanks for any info

Any new updates on this????

[smonkbmw]

the code button light comes on in my car as soon as i connect a battery. my battery has been drained and recharged a few times and it still stays on. the motor (obviously) hasnt been started in months so im not sure what the deal is? and if it saves a code in "memory" wouldnt it lose the code after awhile if the battery has been dead for awhile?

[smonkbmw]

edit: its not my CODE light staying on its the TIMER button. the light stays on even with the car off. if i turn the key to on even in ACC the horn sounds and stays on?! is this the CODE alarm? does it need to be reset? how can i reset it?

[EvoStevo]

Some great info here, guys! I tried the code thing today and spent about an hour trying to remember the code that I set when I got back to the car. I guess next time I should use something easier to remember. I can't wait till my OBC is set properly so I can actually start using it.

[92 mtechnic cabrio]

edit: its not my CODE light staying on its the TIMER button. the light stays on even with the car off. if i turn the key to on even in ACC the horn sounds and stays on?! is this the CODE alarm? does it need to be reset? how can i reset it?

Sounds like you have two separate problems.

To turn the timer light off, switch the key to ACC or ON and select the Timer and then press the SEL-RES. That will turn your timer off. The timer is meant to stay on even when the car is off.

Now when your horn sounds when you switch the key on, it's either because an aftermarket alarm is making it go off or you have a faulty horn switch, or your arm is resting on the horn ;)

[John in VA]

I didn't see Chip Baines' site for OBC operation posted in this thread. Everything is in your owner's manual, but some don't have one.
I believe the only true Easter eggs are the fuel-in-liters & code typ displays - all others are explained in the manual.
No idea about the switch on the back...

13-button OBC operation

[Mr Watsonsilver]

not

Select AVG MPG, not Range.

Its not working for me

[lukem23]

can someone tell me how to change the bulb out of my OBC, i can barley see mine