New Tires Installed-DSC Light on

[JefnZfl]

I got new continentals put on and stopped at the store on the way home. After that stop/start and a few miles later the DSC light came on and stayed on all the way home. It wont go off. I keep waiting an hour or so and go start it again an try to reset it with the button 3 times this evening, an no luck. It wont go off!
Ive tried holding the button down, and just press release.
Would new tires have anything to do with it coming-staying on?
Is there anything else to try, or do I have to go to the local stealer?

[Mirko]

Are you able to read the code? Did any wires get unplugged or cut during the install of the tires?

Is it the DSC light or is it the tire pressure light? Did the shop install the TPMS in rims? Do you have Tire Pressure Monitoring System?

[Finnegan]

It's possible they hit one of the ABS or DSC sensors installing the wheels. Cars 06 or earlier do not have TPMS, and use ABS sensors to detect pressure variance.

Do you have a code reader or access to one ?

[JefnZfl]

Thanks for replys-
no lights when I left tire install shop.
Drove to store. stopped. no lights as I started and began trek home about an hour or so later. A few miles later heading home first the Brake light came on an donged, then the DSC light, and finally the Air Pressure light came on. All in pretty short order-one after the other.
Brake light went off by itself, I reset the Air Pressure light, an attempted to reset the DSC as I drove, but it stayed on. As I said, I had gone out several times last night and started it, trying to reset DSC, but nope- wont go away.
I suppose they could have knocked something about, but theyre aware of and understand the tire pressure monitoring system, and are careful there.
No other service was done. Under hood or otherwise. They replaced run-flats with non-run flats.
Can you reset the dumb computer in trunk by disconnecting the battery for a few secs an reconnect?
I don't have a code reader, Ill keep trying an look around for..I donno...loose wires or somthin.?!?

[The HACK]

What size tire did you put on?

[3002 tii]

Either tires are not the same height (front to rear or side to side)? You sure you're not mixing up TPMS light vs DSC?

[JefnZfl]

225/45 F
245/40 R

Tires are installed correctly, 225's front, 245's rear.
Its the DSC light staying on. Im sure...the lil triangle with apostrophe in middle with arrow wrap around counter-clockwise. I'm sure.
The tire pressure light came on but was able to reset, an stays off.
that looks like a tire, flat at bottom. That's staying off.
DSC light is staying on. That indicates DSC is OFF. How would tires affect that?. I don't understand, must be an unfortunate coincidence or they broke something somewhere. Ill look around carefully then try a Batt on/off reset, only then will I take it in to shop- ptttttfffp

[The HACK]

Were those the original tire sizes? I only ask, because if those were 18s then you're oversized. The OEM sizes were 225/40/18 front, 255/35/18 rear. You list your car as "Z4 SMG," and if my memory serves. the SMG is only available on the 3.0, thus making your tire sizes off and that's what's triggering the DSC fault.

Even if you were running the same size tires as before, I'd still point to the tire size as the reason as to why you're seeing DSC faults. On what used to be our 545i that we sold to my parents, the factory tire sizes were 245/40/18f, 275/35/18r. They suffered a puncture to one of their front tires, and in a pinch I put the two rear tires, 255/40/18, from my MZ4 Coupe on their front. 10mm wider. 3/10th of an inch taller. Smaller than the difference between a completely fresh set of tires vs. a completely bald set of tires.

About a year later my dad calls me and says the car's giving him a weird error about the DSC system. I walked him through how to clear it on the phone and didn't clear the problem. I had him take the car to my mechanic friend to read off the error and reset the computer, and my mechanic reported back that there are hundreds of DSC errors logged in the DME and the computer basically gave up and said "hey! Fix this!" I had him reset the computer, clear out all the error codes, and send my dad on his way.

Another year later, same thing happens, except this time, my mechanic noted that the front tires are nearly bald and needs replacement. That's when I remembered that I had put 255/40/18s in the front, and we replaced it with right size compound.

It's been 2+ years and the same DSC fault hasn't been triggered.

I was surprised at how sensitive the 5 series DSC was, since I was so used to running non OE size tires that are more than 2% different from OE sizes on various BMWs I've owned. Apparently the car won't really mind that there's slight difference from OE sizes, but over time will log the difference in revolutions front and rear if you're more than 1% off in size. I suspect certain DSCs like that on the M is tuned differently to allow for more variances in tire sizes, because I've been running 245F/275R for a very, VERY long time (and frankly, more miles than my parent's 545i).

I suspect that you've been running with the wrong sized tire for a while, and that DSC error log just needs to be cleared out. There's nothing technically wrong with the sizes you've chosen, except they're significantly different from the overall diameter of your OE sizes (unless they're 17"s?)

[donoman]

Are your tires properly inflated?

[3002 tii]

I wonder if one of the TPMS or the system got damaged during tire install.

[Finnegan]

From a bit of reading on this there are a few possibilities. And let's not forget coincidence, which could be in play too.

ABS sensor
DSC sensor
DSC module
Battery

As the ABS sensors are used to measure tire pressure in this model year car, based on small variations in wheel speeds, that's not a bad place to start. It's also the first warning light went off in the sequence. That's another checkmark next to it that indicates this might be the culprit. (This is why Hack and others asked about mismatch tire sizes, and tire pressure.). It could be the culprit, in the sense that it was damaged during install (unlikely), or it could be that the tire sizes are off from the original, as noted in Hack's post.

The sensors are very sensitive to even small changes in battery voltage. This is the part where coincidence could come into play, if there's any reason to believe that the battery might be at fault, I'd measure the voltage and see if that's a possibility.

A BMW specific scanner would tell the story through error codes. The generic OBDII reader isn't going to be able to read the ABS/DSC modules.

[JefnZfl]

would damaged air sensors make the computer turn OFF the DSC?.

To: The HACK: its an 03, 2.5i with SMG. 17" wheel/tires. standard tires 225/45/17 run flats all around.
I put conti's extreme contact DW 225/45/17 Front, (standard size), 245/40/17 Rear. non-run flats. Like I said, air pressure light came on an I reset it no prob. DSC remains on thru many reset tries.

EDIT: let me say at this point that I hate this car sensor nonsense, Its nothing but gdam expensive crap that never works right.
Ive been around cars since I was a kid in the 50's, yes, Im OLD. Granpa's had a lincoln/mercury dealership. One always drove a Mark V, an the other a black Continental with the suicide doors. I rode around in Studebakers. (Yes I rode in an Avanti) as my Dad 'blew out the cobwebs' on the freeway. No seatbelt, I could barely see over the door as the engine roared an the tops of trees an houses flew by ever faster, But I DID have a clear view of the speedometer as we reached 120. on the public freeway. broad daylight. with your kid in the car. an no seatbelts..airbags..none a that. Imagine the consequences nowadays?
And I saw this nonsense from the beginning-the 'coffee can' on the fender under the hood with a lil vacuum line. emission control.
I cant calculate the amount spent over the years on o2 sensors alone. Thousands surely.
My 08 jeep HAS tire pressure monitors. an 4 wheel drive I CANT turn off. I can turn off the stability control, (you have to for four-wheeling, youll freak out the stability ctrl sys) but not the all-wheel drive.
tells me when I need an oil change! I KNOW when to change the oil!! I don't want a car talking to me!!!. an I don't want it 'sensing' anything, OR worst of all-stopping itself! that's insane. Top Gear tested it an it stopped for a hedge, but allowed them to run right into each other head-on. ??.
What if you stop an the 18-wheeler 10,000Gal. gas truck behind you doesn't?. oh shit, that's what. what about driving? paying attention? steering?. The only true safety device is you-your brain.
driving has risks.
Getting in the bathtub has risks.
crossing the street has risks.

I just read an article about the the new Honda something or other had a larger screen than ever! YA!, and performed far more functions than before- COOL!, 94 functions. Problem is the time spent looking down, swiping-then tapping to get to ...say, the fan speed. or radio station.
Too many secs eyes NOT on the road!.
Knobs an switches are better because they only take a sec to manipulate, and memory as to where they are is quickly formed. you don't even have to look to manipulate a knob or switch, if so, it only takes a quick glance.
I remember when knobs were replaced with push buttons. for the radio. that was ten times harder to find the right volume than a knob. Notice knobs have returned.
Remember the seat belts that went up the door by themselves?. Strangled people? trapped people?.
Seatbelt LAW? I HAVE to wear one?. OK, kids must, but so what if I don't want to, Im an adult, if I wanna risk it. You make a law to save me from...myself?. Some states allow no helmets for motorcycles-this, Florida is one a them. ??. but have a seatbelt law?.
Remember airbags were killing people! when they first came out?
I should be able to buy a car without airbags if I want to. And I would.
Ive been in accidents without seatbelts or airbags, I didn't wear seatbelts (no one did) my whole life till they made it a law, even then I didn't a lot.
But I grew up drinking water from the faucet or hose outside, that came into the house thru LEAD pipes, (into the early 70's houses had lead paint/pipes). lived in a lead painted house, breathed leaded gas fumes, rode a bicycle without a helmet, then mini-bikes.. motorcycles. Of course I fell down an crashed. I rolled my Charger into a ditch, crashed motorcyles into a tree, a Camaro, an fell off practicing wheelies. an more. people died. people die anyways. with airbags. with seatbelts. with sensors.

Now were headed down another bad road with these screens-bigger, more functions, and draw eyes off the road more. I sat stopped in a parking lot in broad daylight, and watched a blonde chic in a kia soul run right into the front of my car without ever looking up or braking. guess what she was looking at?.
Phone. Phones are bad enough while driving, now we put a big tablet-type screen built in the dash that does everything?? This is stupidity multiplied by infinity x infinity.
Google has this car drives itself (OGOD help us), well the new version has removed the steering wheel! these boobs are so sure electronic computer gadgetry will work perfectly always an forever they took out the steering wheel! so no human input could be induced into the system manually. Imagine going off a cliff as you hopelessly swipe & tap the screen in front of you, and how cool you thought that was when it came out.
Yet we continue headlong rushing as fast as we can to implement as many of these technologies (sensors/computers) into cars as we can. An people love it. want it.
seriously Im gonna get a 50's big American car, with big chrome bumpers, cancel my insurance, paint it flat black with a pis-can, an let all these idiots run into me with their cars doing the driving. an I wont care, get hurt or fix the dents unless they bend it against a wheel, then Ill beat it or pry it out a lil till it clears, then stand back an laugh at their crumpled piece of tin-covered electronic crapcar, mostly because a what its gonna cost them for each an every dam sensor they have to replace. let 'em sue me, Im old, Ill go into court, drool, an fake dimensia.
suck me sensors.

[itdnwiwbp]

I'm not old and I very much appreciate your rant. I constantly think about getting rid of my M, though I absolutely love it, in favor of an old Jag, Austin Healey, MGA, etc. (reliability be damned!). I'm just afraid of all the little and not so little irritating things that are going to go wrong if I own this car as long as I intend to, indefinitely. Too bad I can't quite, or shouldn't, afford anything that piques my interest enough to consider switching. Good luck with your issue, hope it gets sorted soon.

[Finnegan]

First, the 245/40 tire is a little bit over 1% different than the stock sizes. Assuming the Hack is correct, then the car is going to see that as being a flat tire, and is going to give you a warning, and with both tires being "off" reads it as a larger (DSC) fault.

I believe if you turn the DSC off, can you can have your 1950s style no nanny device car. I think the ABS fault means the ABS isn't going to work either. I'm not 100% sure that either these things, but again I think with the DSC off, and simply ignoring it the fault, the car will still run. albeit w/o those nannies.

I agree with much of what you said about distractions and not paying attention to driving. My track car has no ABS or traction control (well, outside of the driver). The only place I find those devices handy is in very wet weather when ABS comes in handy. Far too much emphasis on technology rather than skill and on distraction vs. paying attention. And as the number of distractions increase all due to technology in the first place, there's a push to add more technology to manage the distractions and make the driver less aware. Ultimately that will and up with none of us being able to drive at all. That's the end state of these folks are driving for. Well driving in a metaphorical sense, since no one will be allowed to drive. For safety reasons of course!

[JefnZfl]

Originally Posted by itdnwiwbp

I'm not old and I very much appreciate your rant. I constantly think about getting rid of my M, though I absolutely love it, in favor of an old Jag, Austin Healey, MGA, etc. (reliability be damned!). I'm just afraid of all the little and not so little irritating things that are going to go wrong if I own this car as long as I intend to, indefinitely. Too bad I can't quite, or shouldn't, afford anything that piques my interest enough to consider switching. Good luck with your issue, hope it gets sorted soon.

I hear ya, Im a big believer in the K.I.S.S. principle-Keep It Simple Stupid.
Too often we ignor this, an now you CANT get anything where this theory has been applied anymore. It honestly didn't take as long to check out of the grocery store in the old days with the old registers, an cash.

My big brother had an red MGA when I was a kid. what a lovely curved beauty, I remember the way it smelled. oil an leather. an the sound.
One grandfather was English and maybe that's why I like these roadsters.
I always had American muscle, but always admired wanted something like this. After many years I found I could afford a used one of these I said hell ya, lets do it. I set a price an looked at comparable rides. I also considered a vette or boxster but when I drove this, I bought it. that day. never drove any BMW or owned anything foreign. I thought the SMG unique an cool.

[JefnZfl]

Originally Posted by Finnegan

First, the 245/40 tire is a little bit over 1% different than the stock sizes. Assuming the Hack is correct, then the car is going to see that as being a flat tire, and is going to give you a warning, and with both tires being "off" reads it as a larger (DSC) fault.

I believe if you turn the DSC off, can you can have your 1950s style no nanny device car. I think the ABS fault means the ABS isn't going to work either. I'm not 100% sure that either these things, but again I think with the DSC off, and simply ignoring it the fault, the car will still run. albeit w/o those nannies.

I agree with much of what you said about distractions and not paying attention to driving. My track car has no ABS or traction control (well, outside of the driver). The only place I find those devices handy is in very wet weather when ABS comes in handy. Far too much emphasis on technology rather than skill and on distraction vs. paying attention. And as the number of distractions increase all due to technology in the first place, there's a push to add more technology to manage the distractions and make the driver less aware. Ultimately that will and up with none of us being able to drive at all. That's the end state of these folks are driving for. Well driving in a metaphorical sense, since no one will be allowed to drive. For safety reasons of course!

But when you go wider tire on the back axle, you have to lower the profile number because its a percentage of the width and tires would be taller in rear.
This is tire rack recommended sizes, an mechanic approved ratio-should be level. I checked with them prior to buying.
This 1% is causing this? Guys are putting much larger/wider than this on the FRONT!
DSC is OFF. that's what the light staying on means: OFF. So the light being on is telling me theres a problem? I thought its a sys on/off light, an its indicating DSC sys Off.

[The HACK]

You should take it to a mechanic with a GT1 type diagnostic machine and have the fault code read. That will answer once and for all what is wrong. I can give all the guesses based on anecdotal evidence, it won't matter a lick unless the trigger for the light is read, understood, and analyzed for a solution.

Or we can all just sit here and throw out more wild @ss guesses. I'm good at that.

[Finnegan]

Originally Posted by The HACK

You should take it to a mechanic with a GT1 type diagnostic machine and have the fault code read. That will answer once and for all what is wrong. I can give all the guesses based on anecdotal evidence, it won't matter a lick unless the trigger for the light is read, understood, and analyzed for a solution.

Or we can all just sit here and throw out more wild @ss guesses. I'm good at that.

Me too. And agree on reading codes. (That's what I suggested in my first couple of posts before going "off roading". Which is fun, but won't get to the heart of the matter.)

[The HACK]

By the way, someone once told me that when a DSC component fails and the the light is on due to an error, then DSC stays ON in diagnostic mode despite the light being on showing it as "off." So it isn't necessarily true that when the light is on, DSC is off.

Just a little tidbit. It was told to us by a 2nd hand source that worked with a National BMW NA representative, that on any modern BMW equipped with DSC, you can FORCE the DSC to stay on by holding down the button for 10 seconds.

I can confirm that it is true. Once I had a student that insist that he's ready to turn off DSC and BEGGED for me to turn it off because it was "holding him back." I begged to differ from the passenger seat. So I told him I'll do him the honor and turn it off for him. Held the button down for 10+ seconds, the light stayed "lit," the student was happy...And I felt DSC kick in every once in a while to save our bacons. Once it's put into "diagnostic mode" DSC can not be reset until the car's turned off.

Shockingly (not to me) those were the smoothest and fastest laps he drove that day. Unfortunately that probably reinforced his sense that he was TOTALLY ready to drive without DSC.

[JefnZfl]

right right, thanks for all the info though, I guess I was hoping some magical easy fix, like hold down sport an beep the horn. lol.,but I kinda knew if I cant reset it, I gotta have take it in. check codes with a box.
A box to tell us what the other box is telling us what the sensor senses. lol. then look it up in a book.
I can tell ya in less n two blocks if DSC is really on or not though.
which brings me back to 'suck it to sensors'
in the old days when it started with all these door dong's we use to find the wire under the seat an rip it out. We thought at the time, whatthaheall we need this dong dong to tell us the doors open?.
seat belts not clicked dong use to go away. now it doesn't.
BTW this thing beeps A LOT when you turn the key off. like 10 times. Loudly. Annoyingly. if Im going in to have them plug into 'the box' for codes on this DSC light prob, Id like that set to Off if possible, probably cant.
Can they adjust shift points with this SMG gearbox? I never use first its so low.
I always start out in second.

[papitosabe]

Originally Posted by Finnegan

It's possible they hit one of the ABS or DSC sensors installing the wheels. Cars 06 or earlier do not have TPMS, and use ABS sensors to detect pressure variance.

Do you have a code reader or access to one ?

my 06 has TPMS..at least I thought it did...maybe it was TWPS ? confused now

[Finnegan]

Originally Posted by papitosabe

my 06 has TPMS..at least I thought it did...maybe it was TWPS ? confused now

Covered in several posts and by some very reliable posters. Could they be wrong? Sure. But not likely. Cars with build dates after Oct 06 have the modules that go inside the tires; cars before do not. Both monitor tire pressure, just using different methods. Both are called TPMS, but only one makes you buy wheel sensors rather than using the ABS.