New E34 Touring Speed Limiter Issue

[Siebenthal]

Hi Guys!

I just bought a 525i touring 1992 today. It came with the original owners manual, cd43 upgrade, both keys + remote, and everything on the car is functional.

On my drive back, I tried to go over 80 just to see how it would drive and this warning light came on the dash and said "Maximum speed 75" and it wouldnt let me get past 80.

How do I turn that off?

[shogun]

you got the original owners manual, read it, it is just a warning set on the OBC http://750il.bmw7.hu/owners_manual/images/page_048.jpg

[ross1]

Obviously I seldom have used that feature as I didn't know it would actually limit speed. I thought it only would annoy you into slowing down or turning it off.
Great feature for those with lead footed teens. Glad this wasn't available when I was one of them.

[shogun]

I never used it so far, I assume it is just a warning light but will not limit speed. But he can test it by switching it off.

[Siebenthal]

Thank you! I figured it out and it hit 110mph just fine.

[zkd]

Hi Guys!

On my drive back, I tried to go over 80 just to see how it would drive and this warning light came on the dash and said "Maximum speed 75" and it wouldnt let me get past 80.

How do I turn that off?

I've never seen this that the car won't go past maximum speed set by OBC, mine just gives gong and flashes the limit on the cluster. how do you do it? how did you turn it off?

[Layne]

It does not limit the car's speed, it's just a warning.

[ross1]

It does not limit the car's speed, it's just a warning.

My recollection too but haven't used it for decades. I think the OP misspoke about "not letting" him exceed 80

[Siebenthal]

It really didnt let me go past 80. When I push the pedal all the way, it goes from 75

1) bling sound - maximum speed 75
2) I further push the pedal in and it hits 80
3) thats what it stays at and it wont let me go further.

The way I "unlocked" it is I fiddled with the computer and theres like these buttons 1000/100/10 and when I pressed it it said 075, 100 (i think) and 175.
Once I set it to 175 I tested it on the highway and got to 110mph (i think it can hit 120 but there was traffic)

Whats the top speed on one of these anyway?

[Mykk]

That is interesting. I've seen the speed limiter in the hex code of the programming used by the chip in the DME, but didn't realize it was able to be modified by external hardware without burning a new chip with the changed tuning. Cool.

[Layne]

It really didnt let me go past 80. When I push the pedal all the way, it goes from 75

1) bling sound - maximum speed 75
2) I further push the pedal in and it hits 80
3) thats what it stays at and it wont let me go further.

The way I "unlocked" it is I fiddled with the computer and theres like these buttons 1000/100/10 and when I pressed it it said 075, 100 (i think) and 175.
Once I set it to 175 I tested it on the highway and got to 110mph (i think it can hit 120 but there was traffic)

Whats the top speed on one of these anyway?

That is absolutely not what happened, sorry. Maybe a cheeto rolled under the accelerator pedal at that moment.

[zkd]

I am astonished. I have been fiddling in that car top to bottom, there is nothing that will limit the speed. the only way to do it is have external hardware or reprogram the DME. which in my view will be very difficult and not good for the car because it has to limit the fuel to the injectors or limit the spark.. or you will need electric throttle control like the one with the cruse control.

that's the only way I can think of it. Layne is spot on.

[Mykk]

I'm not gonna tell this guy he didn't experience something he did. We weren't there....we don't know what happened.

- - - Updated - - -

...reprogram the DME. which in my view will be very difficult and not good for the car....

Not the case, it's a fuel cut that reenables after a speed decrease. Not tough to change, it's one byte of information in the code.

[zkd]

Not the case, it's a fuel cut that reenables after a speed decrease. Not tough to change, it's one byte of information in the code.

but how to get it to interact with the OBC?

a throttle inhibitor is much easier, which can be connected to the OBC which will control it via the Dong signal.

[Siebenthal]

Im sorry - I dont mean to try and make something up or anything. Its genuinely what I experienced. However, in light of this I will try it again.

Sorry about that.

[zkd]

Im sorry - I dont mean to try and make something up or anything. Its genuinely what I experienced. However, in light of this I will try it again.

Sorry about that.

no need to apologize, we are intrigued.

my question is can you repeat the process, maybe a video will help... this is very interesting.

[ross1]

FWIW
I just finished using the limiter in my '89 535. My gong was silenced long ago so I had no audible warning but the red indicator next to the limiter button on the OBC began blinking when I exceeded the set speed. I was able to drive the car well in excess of the set "limit" speed without any interference.

[Mykk]

In case anyone is interested, looking at an E34 525i 413DME. This is the byte for the speed limiter, viewing the code in decimal gives the exact KPH the speed limiter is set to...201KPH, roughly 125MPH. The value is the same as in the 402 DME used in the 92-93 525i's

[zkd]

ok how does this help.. it's an over all Electronic limiter.. not OBC limiter. therefore you can not set it through OBC.. or can you?

[Mykk]

ok how does this help.. it's an over all Electronic limiter.. not OBC limiter. therefore you can not set it through OBC.. or can you?

At this point I'm just confirming your original sentiment.

[Siebenthal]

Hi guys! I tested the car again today. I was wrong. The car is not limited to 75mph.

The reason why I thought so in the very beginning was because my pedal has two stages. stage 1 (1%-90%)

From 90-100% you have to push in a little harder than 1-90.

The night I bought it/wrote this article, I guess I didnt push the pedal all the way and thats why it didnt go over 80.

Sorry for saying that it didnt go over 80 and for all the confusion etc.

[shogun]

Check the bushings of your throttle pedal, they might be broken, have replaced the bushings on my car some years back.
08 Bushing D=12,2MM 2 35411154172 http://www.realoem.com/bmw/enUS/show...diagId=35_0136

[Onizukachan]

Hahahahaha.

seriously, what's wrong with your car that you can't do the speed limit without depressing the pedal to kick down?

Nothing this person says seems factual. At all.