[dcmac]

Hi guys,

Pulled out of my garage today and got some weird errors all at once that I can't figure out. Here's what I'm getting:

1. Chassis Stabilisation "drive moderately"

2. Daytime Pedestrian Warning Limited "brake intervention not possible, but visual and acoustic warnings are still active"

3. Frontal Collision Warning System "Malfunction. Brake intervention not possible. Visual and acoustic warnings active."

4. Brake system: "stop carefully" DSC light on.

Other points to note:

- Car stops fine and pedal feel is good but with the above errors, it won't let me change drive modes.

- I changed out my pads a few weeks back (fronts and rears) and have had no problems. A couple weeks back my race shop did a full fluid flush, also no problems. I have always had the sensors disconnected as I track the car, so I'd be surprised if this is some sort of brake sensor issue as I've never had that happen.

My forum research to date points to various issues this could be across different BMW platforms. Some have said the errors go away after a restart (mine didn't) or after leaving the car for a few hours (I'll see if that helps).

Some have said it's due to the sun causing issues with the camera in front of the rear view mirror that controls the collision systems - or the cam itself being faulty - and/or a faulty sensor somewhere around the rear diff (?).

Others have noted more serious things like getting their steering rack replaced (!!?) which just seems crazy to me.

My car is an '18 M2, I've had no problems with it till this.

Any insight appreciated - thanks.

[5.M0NSTER]

This indicates a problem with the Stability Control/Traction control/ABS system. It’s all one unit.

Is the ABS or TCS lights on? Or just Dynamic Stability Control?

Could be an input to the system like Yaw Rate Sensor, or a CAN connection problem. Did you have all the codes pulled? I would expect a more specific fault code for a sensor or communication issue

[5.M0NSTER]

Also a wheel speed sensor problem could cause it too. Did you inspect the wires going to the wheels when you changed pads? How are the pad wear sensors looking?

[m3username]

Just want to echo 5.M0NSTER, pulling the codes will be your best bet. The errors you're getting also are similar to what comes up after coding the ECU so they correspond to a whole host of failures.

The code will be the quickest pointer. Regardless it does sound like something may need to be fixed, best of luck.

[zkeeper]

Might wish to have your dealer put it on a electrical check for full voltage...a lowering battery can bring up dash signs that though it runs OK...its not got enough vitamins. Yours is an 18 M2, so batt ought NOT be an issue...but it could be as simple as that. We have had that.

[///M TOWN]

Originally Posted by zkeeper

Might wish to have your dealer put it on a electrical check for full voltage...a lowering battery can bring up dash signs that though it runs OK...its not got enough vitamins. Yours is an 18 M2, so batt ought NOT be an issue...but it could be as simple as that. We have had that.

Agreed

Exactly why my battery is always plugged in when my car isn't being driven

[bimmer98]

I had a bunch of failures like this on my 135i once and come to find out the trunk was full of water somehow and it fried everything.

[dcmac]

Originally Posted by 5.M0NSTER

Also a wheel speed sensor problem could cause it too. Did you inspect the wires going to the wheels when you changed pads? How are the pad wear sensors looking?

Think I found the issue. Rear left caliper leaking fluid badly, bleed nipple screw not tightened. Master resovoir almost dry! That said good chance air is in the system and I have a feeling the caliper being emptied led to the other codes. Taking it back to my shop, they are going to flush it and pull codes and see what we find.

[dcmac]

Originally Posted by 5.M0NSTER

This indicates a problem with the Stability Control/Traction control/ABS system. It’s all one unit.

Is the ABS or TCS lights on? Or just Dynamic Stability Control?

Could be an input to the system like Yaw Rate Sensor, or a CAN connection problem. Did you have all the codes pulled? I would expect a more specific fault code for a sensor or communication issue

Yeah, pretty sure it’s the ABS. Air in it, sending it a bit bonkers along with stability control etc.

Do you guys know if these errors are able to be cleared without me having to go to the dealer? We will pull the codes but I’m not aware of what happens once you find the problem. If we flush the lines and get it back to normal is there a chance these warnings just go on their merry way and disappear?

[dcmac]

Reporting back for anyone that might ever have the same problem. We did a full flush then manually pumped more clean fluid through each line and removed a lot of air from the system. Pulled the various codes, cleared them, went for a drive and the car is back to normal. Hopefully stays that way. Thanks for the replies to my initial post !

[5.M0NSTER]

Sweet, glad it wasn’t too hard of a fix and you didn’t run out of brake fluid. Thanks for updates about what happened.

[pal]

Originally Posted by dcmac

Think I found the issue. Rear left caliper leaking fluid badly, bleed nipple screw not tightened. Master resovoir almost dry! That said good chance air is in the system and I have a feeling the caliper being emptied led to the other codes. Taking it back to my shop, they are going to flush it and pull codes and see what we find.

I am surprised you had any hydraulic pressure at all with this condition and how you did not feel this in the pedal. With one open bleed screw, your pedal should have gone to the floor - kinda like when you bleed calipers.

[CalAcacian]

Originally Posted by dcmac

Yeah, pretty sure it’s the ABS. Air in it, sending it a bit bonkers along with stability control etc.

Do you guys know if these errors are able to be cleared without me having to go to the dealer? We will pull the codes but I’m not aware of what happens once you find the problem. If we flush the lines and get it back to normal is there a chance these warnings just go on their merry way and disappear?

It's possible to do so if you clear them yourself, but they may still show up on a dealership key read. I would fix the issue and bring the car to the dealership so they can pull the codes and note it. If you wait too long it is possible they will blame you for later brake issues and attempt to decline warranty coverage or liability for Song-Beverly.

Dealer records are your friends, just make sure you go over the jobs line by line and think that they accurately reflect the history of the issue. I often make them rewrite them to ensure that what I am signing is accurate. A little bit of effort now can be worth tens of thousands if things go wrong later.

[dcmac]

Originally Posted by pal

I am surprised you had any hydraulic pressure at all with this condition and how you did not feel this in the pedal. With one open bleed screw, your pedal should have gone to the floor - kinda like when you bleed calipers.

The bleed nipple wasn’t “completely” loose but it was far from secured. The pedal didn’t feel great but it wasn’t to the floor. I think had it been one of the front calipers it would have been much more noticeable.

[dcmac]

Originally Posted by CalAcacian

It's possible to do so if you clear them yourself, but they may still show up on a dealership key read. I would fix the issue and bring the car to the dealership so they can pull the codes and note it. If you wait too long it is possible they will blame you for later brake issues and attempt to decline warranty coverage or liability for Song-Beverly.

Dealer records are your friends, just make sure you go over the jobs line by line and think that they accurately reflect the history of the issue. I often make them rewrite them to ensure that what I am signing is accurate. A little bit of effort now can be worth tens of thousands if things go wrong later.

We cleared them, and they haven’t returned. It was clear it was related to the lost brake fluid and air in the system, so I don’t see the need to bother my dealer. I get your point though. I keep my car in top shape and would take it in if I thought it was something serious. At the same time, it’s a modded car and less trips to the dealer the better (even though my dealer is great!).