DSC Light

[BCS_ZHP]

So my wife was driving the coupe yesterday, someone overran a stop sign from a side street, she successfully made an evasive swerve while braking and the DSC light came on. I tried to reset it last night to no avail, tried it both when the car was parked and while moving. So drove it and nothing seemed amiss, the car braked fine, didn't lose rear end traction when I tried - DSC was definitely engaged. Told her to drive it today and after 10 miles or so try holding the DSC button to reset while driving. She did but the light still persisted. Then she stopped, dropped off our daughter, came back and when she restarted the car the light was off. She's done a couple of more on/off cycles and the light remains off. Morale of the story, if your DSC light comes on be persistent in your reset attempts before you haul it to the shop.

EDIT: spoke too soon, a simple reset didn't fix it, will add the fix when it is found.

[ELCID86]

Glad she is safe. Hope it stays off.

[BCS_ZHP]

Well, didn't stay off for long, it's lit up again. Any ideas where to start troubleshooting?

[derbo]

ever tried to pull the code on the car to see whats faulting?

Wild guess: It sounds like that evasive swerve cause something to get loose.

[Hornung418]

Guessing its out of alignment somewhere or a possible sheel sensor has shifted loose.

From a GS3, this was sent.

[BCS_ZHP]

Did some surfing research last night and talked with Jon E., he has experienced this before on a family member's car.

As an update, the DSC and Brake light are both lit Yellow. Jon said that culprits can be dirty or bad wheel speed sensors and/or a bad ABS control module. The ABS module is a $1000 part but it can be rebuilt for $200-250. I'm going to try cleaning the wheel speed sensors first to see if that corrects it (fingers crossed). If not, then will try to figure out how to isolate/confirm its really the ABS control module. And if it is, I will likely go the rebuilt vs. new route.

More updates to follow.

[derbo]

Good luck Bruce.

Do you have access to a BMW Diagnostic computer?

[BCS_ZHP]

Good luck Bruce.

Do you have access to a BMW Diagnostic computer?

Have the little Peake tool, it shows no codes. Going to have to pay a local Indy to really read this car.

[derbo]

With all these e46s, and the mafias help, I think you should get a laptop working for diagnostics. :)

Real reason I got my laptop setup was for NCSexpert options, but lately after setting everything, it just serves as a big BMW specific diagnostic reader.

[derbo]

But definitely speed sensor would be the first to check.

I have both dsc and brake on yellow when my m3 swap was done. The speed sensors were not attached in the rear and I got the lights.

[BCS_ZHP]

With all these e46s, and the mafias help, I think you should get a laptop working for diagnostics. :)

Real reason I got my laptop setup was for NCSexpert options, but lately after setting everything, it just serves as a big BMW specific diagnostic reader.

I am an IT challenged individual, this old dog can't understand all that high tech, my 16 y.o. takes care of all things IT for our family.

[wsmeyer]

+1 for some sort of code reader.

If you have an Android phone you could use one of these:

http://www.amazon.com/gp/product/B0090ZJPMK/ref=olp_product_details?ie=UTF8&me=&seller=

and the Torque app to read and clear codes as well as see live data from the ECU. That setup would work on all your Beemers except the X5

[BCS_ZHP]

Got home late, jacked up the rear & removed the wheels, then used the air compressor to blow it out in the area of the wheel speed sensors. Reattached wheels, let it down, tried to clear yellow lights, started it, still there.

Now frustrated, got lazy & didn't turn the car around in the garage, jacked up front right corner, turned the wheel and left the wheel installed, climbed under there and attempted to blow it out with air. Was pretty tight so decided to loosen the bolt holding the wheel speed sensor to try to pull it out & clean it. Mistake, bolt was rusted and snapped it, will have to extract & correct that on Sunday. Went to the left front and blew it out with air. Reset the lights, took the car for a 30 minute/20 mile ride afterwards, no lights, appears to be back to normal.

Not counting my chickens before they've hatched, now I have a broken bolt to extract & replace but if I got out of this for this little bit of time invested plus just a broken bolt to replace, I will be quite happy and quite surprised. Oh, and when blowing out with air on one wheel I did get a bunch of little tiny pieces of chewed up paper, that probably was the culprit.

[danewilson77]

What exactly did you blow out without removing the speed sensor?

Good werk Bruce.

HTC DNA, Williamsburg, VA

[BCS_ZHP]

I could see where the speed sensor made contact to the inner hub that has like gear teeth, put the air nozzle there and blew 120 psi, dust and crap flew everywhere.

[danewilson77]

I could see where the speed sensor made contact to the inner hub that has like gear teeth, put the air nozzle there and blew 120 psi, dust and crap flew everywhere.

Ok. Understand.

HTC DNA, Williamsburg, VA

[BCS_ZHP]

Cheap fix, if it continues to work I'm one happy guy.

[derbo]

Hopefully that solved it. Its interesting that the ABS rings and the speed sensor are exposed to the elements like that.

[BCS_ZHP]

Update, it didn't work, the lights came back on today. So took it to an Indy and they took it to me. Charged me one hour labor to read the codes and diagnose it was exactly what I said it was, and then charged me another hour to extract and replace that broken bolt (didn't have any time, was traveling this week). Was forewarned that while the lights cleared there was no assurance that they wouldn't come back on which would kind of indicate that it's likely the DSC module which costs close to a grand. Drove it yesterday and today, no issues until I hit the 75-80 mile mark since they cleared all codes and then the DSC & brake lights came on yellow this evening. 10 miles later the SES light came on and it ran like crap, missing and no power. I limped it a couple more miles and then the SES went out and the car ran perfectly again but DSC and brake lights remained yellow. Im getting CAN buss error codes that i don't understand. As much as I don't like it, thinking going to have to take it to the dealer for at least a diagnosis, and then will determine what to do next.

[johnrando]

Ouch. Hope it works out for you.

[Avetiso]

Shoot.


Sent from my iPhone using Tapatalk 2

[330i ZHP]

in for updates - I hope it doesn't get too $$

[BCS_ZHP]

Update -- drove it 4 days this week, no lights, no codes, was starting to get happy. Last night on the ride home, after more than 200 miles since the light was last on, hit an interstate off ramp at speed but nothing excessive and the light came on in the middle of the off ramp curve. Have an appt at the dealer for 1 pm today, at least get the assessment and find out what the heck this is.

[jsfbmw]

Update -- drove it 4 days this week, no lights, no codes, was starting to get happy. Last night on the ride home, after more than 200 miles since the light was last on, hit an interstate off ramp at speed but nothing excessive and the light came on in the middle of the off ramp curve. Have an appt at the dealer for 1 pm today, at least get the assessment and find out what the heck this is.

Wouldn't you know it, yesterday I was taking an off-ramp and half-way through the arc I hear a beep and my DSC and Yellow Brake light up. Just as described here. Drove for about 20 minutes and got to a red light. Turned car off and then on, lights were out. Still out today.

Hope you find the cause for your issue and that it's not $$. Hope I don't have what you have.

[BCS_ZHP]

Here's the latest -- was diagnosed as bad ABS/DSC pressure sensors. There are 2 of these sensors on the bottom of the brake master cylinder. I riddled the dealer's service writer with questions about how we could be certain it was these 2 sensors and not the more expensive ($1K) ABS control module, I wanted to understand. I guess when he asked the technician these questions, the tech must have realized I wasn't the normal guy just whining about the cost but rather an enthusiast trying to figure out why I'm having this issue. The technician actually called me yesterday, talked me through the faults he's seeing, why he believes its the 2 pressure sensors, how these sensors function in the ABS/DSC system, etc. And he asked me for the complete background on the who/what/when/why it happened, any recurrences, any other issues, he wanted to fully understand what perpetuated this situation. From that discussion, he said he's 99% positive it's the 2 sensors and not the ABS control module. Actually he said in the almost 13 years since the e46 was introduced, he's only replaced the expensive ABS control module on one car but he's replaced these ABS/DSC pressure sensors in dozens if not hundreds of e46s. (He told me the expensive ABS control module is more prone to fail on e38/39s, almost never happens to an e46.).

Next I asked about what was involved with replacing these sensors (they're $143 each thru the dealer and I can get them at $107 each wholesale), how much time/labor. He said its about a 3 hour job, and a PITA. He asked me who did my brake job as he had noticed the S&D rotors, SS lines and ATE blue racing fluid. i told him I did it and he said that I could probably accomplish it myself but likely wouldn't want to. He said the master cylinder has to be removed, you're going to lose all your brake fluid, air is going to get into the lines and can potentially foul up the ABS. He said its a messy job that you really need a lift for because you're going both under the car & under the hood, said sometimes you have to bleed the system 3 or 4 times to get all the air out. And then he offered that if I could get him a couple of cans of ATE Blue up to the shop, he'd use that for filling and bleeding my system. Unfortunately I couldn't get it to him quick enough so they'll use regular DOT 4 fluid and he told me to just re-bleed the system later when I get my preferred fluid.

I was impressed that the technician took the time to call me, explain it to me, and work with me. My bill is going to be just under $900 and the car will be ready this afternoon. Will post an update after I get it and drive it.

Bruce

[ELCID86]

Glad you are on track to get it sorted out. Did he give any indication of why they would both fail when they did (hard braking and a swerve)? Name of the dealer? I think their customer care is worth noting here so those of us in the area can use them when the time comes. That's cool that he called and that he offered to use your fluid.

[BCS_ZHP]

Shawn,
The car is at Fairfax BMW in Northern Virginia, I think the senior technician's name was Pat (I'll note it when I get the receipt), my service advisor was Allen who is a fellow e46 owner/enthusiast. Allen will give you his personal cell # so you can text him for updates on your car's progress.

I asked about what causes them to fail, the swerving incident or just age. He said some fail and some don't, he didn't have a good explanation, but he said they normally both fail. Then he noted that if you've got the master cylinder off to replace one, and you're an enthusiast, you're going to replace both anyway, agreed.
Bruce

[Jon D]

Thanks for this. Mine just went into the same mode. Off to Indy Friday

[BCS_ZHP]

Allen my service advisor just texted, the car is ready for pickup. And more good customer service, he reminded me to bring my BMWCCA card so a discount can be applied at the cashier. :)

[danewilson77]

Allen my service advisor just texted, the car is ready for pickup. And more good customer service, he reminded me to bring my BMWCCA card so a discount can be applied at the cashier. :)

BMW CCA is that organization that requires you to pay, to be a member of, correct? OK. Right. Just checking.

[derbo]

Glad the technician was about to help you understand what it was. There are less and less of these guys out there willing to take the time to explain things to the customer anymore.

[Avetiso]

Glad the technician was about to help you understand what it was. There are less and less of these guys out there willing to take the time to explain things to the customer anymore.

+1! This is so true.

Sent from a junkyard via GS4.

[BCS_ZHP]

BMW CCA is that organization that requires you to pay, to be a member of, correct? OK. Right. Just checking.

Don't remember what they cost for membership, and I sorely recall how they treated us, but it gets me 25% off parts at my local dealer and 15% off tonight's bill, so for that I'll keep being a member. I bought almost $10K in parts & service last year according to my AMEX end of year summary, so the card saved me nearly $2K.

[danewilson77]

Don't remember what they cost for membership, and I sorely recall how they treated us, but it gets me 25% off parts at my local dealer and 15% off tonight's bill, so for that I'll keep being a member. I bought almost $10K in parts & service last year according to my AMEX end of year summary, so the card saved me nearly $2K.

#sarcasm

#cantshakethebitterness

Sent from my HTC6435LVW using Tapatalk 2

[BCS_ZHP]

Life's too short bro, discard the probs, embrace the joys. And this place is pure joy, I'd kiss you right now if you were here.

[danewilson77]

Life's too short bro, discard the probs, embrace the joys. And this place is pure joy, I'd kiss you right now if you were here.

I'd let you as long as you smacked me on the ass!

Sent from my HTC6435LVW using Tapatalk 2

[johnrando]

Life's too short bro, discard the probs, embrace the joys. And this place is pure joy, I'd kiss you right now if you were here.


#sarcasm

#cantshakethebitterness

Sent from my HTC6435LVW using Tapatalk 2

#sureit'stooshortbutstillfuntotakeshotsatthembased ontheirpolicy

[danewilson77]

#sureit'stooshortbutstillfuntotakeshotsatthembased ontheirpolicy

#agree

[Jon D]

Here's the latest -- was diagnosed as bad ABS/DSC pressure sensors. There are 2 of these sensors on the bottom of the brake master cylinder. I riddled the dealer's service writer with questions about how we could be certain it was these 2 sensors and not the more expensive ($1K) ABS control module, I wanted to understand. I guess when he asked the technician these questions, the tech must have realized I wasn't the normal guy just whining about the cost but rather an enthusiast trying to figure out why I'm having this issue. The technician actually called me yesterday, talked me through the faults he's seeing, why he believes its the 2 pressure sensors, how these sensors function in the ABS/DSC system, etc. And he asked me for the complete background on the who/what/when/why it happened, any recurrences, any other issues, he wanted to fully understand what perpetuated this situation. From that discussion, he said he's 99% positive it's the 2 sensors and not the ABS control module. Actually he said in the almost 13 years since the e46 was introduced, he's only replaced the expensive ABS control module on one car but he's replaced these ABS/DSC pressure sensors in dozens if not hundreds of e46s. (He told me the expensive ABS control module is more prone to fail on e38/39s, almost never happens to an e46.).

Next I asked about what was involved with replacing these sensors (they're $143 each thru the dealer and I can get them at $107 each wholesale), how much time/labor. He said its about a 3 hour job, and a PITA.. He said the master cylinder has to be removed, you're going to lose all your brake fluid, air is going to get into the lines and can potentially foul up the ABS. He said its a messy job that you really need a lift for because you're going both under the car & under the hood, said sometimes you have to bleed the system 3 or 4 times to get all the air out.

I was impressed that the technician took the time to call me, explain it to me, and work with me. My bill is going to be just under $900 and the car will be ready this afternoon. Will post an update after I get it and drive it.

Bruce

So I just heard from my guy at the Indy... it's the exact same description... only difference is the 3 hours cost less... :) .... but it's still a $600 bill.. :(... indicated 90+% of the time that solves the problem but .. there's a small chance it's the ABS module.. keep your fingers crossed.

And what's funny is they did a brake job a few months ago.. performance rotors/stainless lines etc.. so they didn't ask me who did the work... but everything else was an identical conversation.. too funny

[Jon D]

Well all fixed.. $600 later... and no faults on the 5 mile drive home

[BCS_ZHP]

Mine was almost $900 sticker price, they gave me a BMW CCA discount to $750. Over a hundred miles so far and no issues. Also tossed it into the off ramp hard last night & tonight, she handled it fine, no lights or issues, thinking its fixed.

[Jon D]

Just had a funny thought, we both had failures after brake jobs with stainless lines. Wonder if something in the increased rigidity of the hose caused the failure?


Sent from my iPad using Tapatalk HD

[derbo]

My gf's mom's 325xi just got random DSC and Brake light pop up. This thread may help!


Bruce, do you know what dianostic codes you had during the talk with the tech ?

I pulled codes from the 325xi and got these

2A GM: Relay Central Locking, double locking
91 EGS: CAN torque reduction
76 DSC: DME/DDE does not fulfil torque request
1C IHKA: AUC sensor
BE KOMBI : Data-filing difference to central light module
8F KOMBI : Overvoltage
22 LSZ2: Headl v.a.c., front load sens, sh.circ.toearth


I figure the EGS and the DSC are related, everything else I think are other problems to be addressed.

[BCS_ZHP]

Derek,
Here are the codes from the diagnosis received from my Indy, but he wasn't sure if it was the DSC pressure sensors or the ABS control module:
-5E1A: CAN data error from DME
-5E19: CAN data error from DME
-5E21: Pressure sensron 2

And the dealer doesn't give you much:
Two 34-52-1-164-458 DSC pressure sensors: 345030 @ $143.47 each
About $500 for 4 hrs labor
Description: 75903 pressure sensors on brake master cylinder have failed cc 3.50 performed short test on vehicle and found faults stored in the DSC control unit for brake pressure sensors. Replaced both brake pressure sensors and bled complete braking system. Cleared fault memory and road tested vehicle with no issues.

The work was performed on Aug 7th, 2K miles since then with no further issues, the car appears to brake stronger since the repair. Hope something here will help you diagnose it.
Bruce

[derbo]

Derek,
Here are the codes from the diagnosis received from my Indy, but he wasn't sure if it was the DSC pressure sensors or the ABS control module:
-5E1A: CAN data error from DME
-5E19: CAN data error from DME
-5E21: Pressure sensron 2

And the dealer doesn't give you much:
Two 34-52-1-164-458 DSC pressure sensors: 345030 @ $143.47 each
About $500 for 4 hrs labor
Description: 75903 pressure sensors on brake master cylinder have failed cc 3.50 performed short test on vehicle and found faults stored in the DSC control unit for brake pressure sensors. Replaced both brake pressure sensors and bled complete braking system. Cleared fault memory and road tested vehicle with no issues.

The work was performed on Aug 7th, 2K miles since then with no further issues, the car appears to brake stronger since the repair. Hope something here will help you diagnose it.
Bruce


Thanks Bruce. Since the KOMBI also mentioned overvoltage, I need to run a quick test of the alternator to make sure the voltage regulator is operating correctly. It may be related. I didn't see the sensor as a fault so it might not be that.