Z3MCoupe.com Forums

Go Back   Z3MCoupe.com Forums > M Coupé Technical > Technical Discussion
HOME Gallery Register Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #11  
Old 03-08-2018, 01:28 PM
Jon_Bmw Jon_Bmw is offline
Senior Member
 
Join Date: Nov 2007
Posts: 127
Default

Yes I feel your pain, with a young child now my spanning/tinkering hours are severely limited! The enthusiasm is going.

A really quick check you can do with most ABS sensors is to check the resistance across them. You don't even need to remove the sensors, simply unplug them and stick an ohm meter across them. From memory you should be looking for about 0.8-1.2Kohms (google this as a electrics aren't really my thing!). If any are open circuit then they are dead.

I would be surprised if any were dead or else you ABS light would be on as well. I always start on the LHS of the vehicle as this side gets the crud off the side of the road flung at it.

Is the car dry stored as some Z3 owners suffer water ingress that ends up in the foot well where I think the YAW and acceleration sensors are. Given the weather we have had recently I doubt this is the issue either.
Reply With Quote
  #12  
Old 03-08-2018, 04:31 PM
exdos's Avatar
exdos exdos is offline
Senior Member
 
Join Date: Aug 2003
Posts: 4,820
Default

Problem is I'm getting old and crawling around on floors isn't as easy as it used to be and I maintain a few vehicles and a couple of go-karts so the novelty has long-since worn off!

I've had my MC since 2003 and used it loads in the first few years but I'm afraid because of low mileage S54 MCs increasing in value so much, it's become a garage queen and only done 400miles in the last 4 years. I've examined all the wheel sensors and they are in top shape. The car is immaculate and clean inside and out and is bone dry.

I now need to dig deeper. I've ordered a cable and INPA and I'll find a PC somewhere and my next move will be to run that.

Whilst researching the problem I came across this thread: https://www.e90post.com/forums/showthread.php?t=545976
The second post is interesting, so I've checked the ABS fuse box and found that my MC has exactly the same part number Blue Relay, so I'll probably give that a try after scanning the ECU. Another post in that thread says that the Porsche 944 had a similar DME relay issue. So perhaps that might prove to be the problem?
__________________
/// Exdos ///
"Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart
Reply With Quote
  #13  
Old 03-08-2018, 07:49 PM
Walk Walk is offline
Senior Member
 
Join Date: Jan 2015
Posts: 137
Default

If you don’t have the ABS light on it’s not going to be a faulty wheel speed sensor.
Your fault is within the DSC part of the system, steering angle, yaw sensor etc
If you have had the tacking done recently or someone has realigned the steering wheel the steering angle sensor needs recalibrating.
Personally I think your wasting your time guessing what the fault could be, & May cause more problems disturbing sensors that have been there for 15 years plus, it needs the memory reading with proper BMW software.
Reply With Quote
  #14  
Old 03-08-2018, 08:03 PM
exdos's Avatar
exdos exdos is offline
Senior Member
 
Join Date: Aug 2003
Posts: 4,820
Default

Quote:
Originally Posted by Walk View Post
If you don’t have the ABS light on it’s not going to be a faulty wheel speed sensor.
Your fault is within the DSC part of the system, steering angle, yaw sensor etc
If you have had the tacking done recently or someone has realigned the steering wheel the steering angle sensor needs recalibrating.
Personally I think your wasting your time guessing what the fault could be, & May cause more problems disturbing sensors that have been there for 15 years plus, it needs the memory reading with proper BMW software.

As I said, the car has only done 400 miles over the last 4 years, but I do to take the car out for a 10 mile run to get the oil to temperature every 2-3 weeks and switch everything in the dash to keep everything working and I've maintained the car, to avoid problems from lack of use. The geometry hasn't been adjusted for several years so this problem has come out of the blue. The car hasn't been neglected or just left alone.

Once I get the INPA running I should be pointed in the right direction.
__________________
/// Exdos ///
"Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart
Reply With Quote
  #15  
Old 04-08-2018, 04:15 AM
Walk Walk is offline
Senior Member
 
Join Date: Jan 2015
Posts: 137
Default

If your getting software I’d suggest ISTA, that’s the newer BMW diagnostic software, or even the older version that was used when these cars were new DIS.
It will show guided fault finding, telling you exactly what to check & what to replace. Also has the facility to calibrate steering angle sensor.
Reply With Quote
  #16  
Old 11-08-2018, 01:29 PM
exdos's Avatar
exdos exdos is offline
Senior Member
 
Join Date: Aug 2003
Posts: 4,820
Default

I've now got INPA and the lead set up.

The ASC/DSC is throwing fault code "166 Pressure Sensor 2". Apparently the sensors are at the side of the master cylinder and access looks a bit tight. So I'll investigate that further.
__________________
/// Exdos ///
"Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart

Last edited by exdos; 11-08-2018 at 01:32 PM.
Reply With Quote
  #17  
Old 11-08-2018, 06:52 PM
Jon_Bmw Jon_Bmw is offline
Senior Member
 
Join Date: Nov 2007
Posts: 127
Default

A very long shot but could be something similar to this;

https://youtu.be/De5mY0cObyg

Do it with the ignition off! Read the comments.

I'm just wondering if it is linked to the MOT and the fact it's been on the brake rollers. Highly unlikely and I can't really think of a genuine link even if they ran the rears with the LSD.
Reply With Quote
  #18  
Old 11-08-2018, 07:30 PM
exdos's Avatar
exdos exdos is offline
Senior Member
 
Join Date: Aug 2003
Posts: 4,820
Default

All the electrical connections for the ABS/DSC and pressure sensors are tucked under the brake cylinder and it looks as though I'll have to empty the cylinder of fluid, disconnect a couple of brake pipes and then remove the cylinder and stuff to get access to remove all the connectors. If I need to do that, I'll also fit a pair of new sensors whilst I'm at it: it'll cost about £40 for the parts, so a cheap repair if it works.
__________________
/// Exdos ///
"Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart
Reply With Quote
  #19  
Old 13-08-2018, 03:20 PM
exdos's Avatar
exdos exdos is offline
Senior Member
 
Join Date: Aug 2003
Posts: 4,820
Default

When I hooked up the MC to INPA on Saturday morning the DSC did actually get knocked off, but not by anything I did specifically to adjust any settings, so I had no idea what did this. I then took the car for a test drive and I could switch the DSC off/on at will. When I got back, I decided that I'd hook the car up again to see if there were any new fault codes and the DSC came back on permanently and I couldn't knock the light off no matter what.

This afternoon I hooked the car up again and this has again knocked off the DSC light and all I've done was, in INPA, open the ABS/DSC function with the E46 chassis files (there are none specifically for the Z3 or MC). I'm going to leave it at that until/if the DSC light comes on again and then I'll change the pressure sensors. I can't think of any logical explanation other than making outside electrical connection has zapped the Gremlins lurking in the DSC module.
__________________
/// Exdos ///
"Men who try the impossible and fail spectacularly are infinitely superior to those who reach for nothing and succeed" --Napoleon Bonapart

Last edited by exdos; 13-08-2018 at 03:23 PM.
Reply With Quote
  #20  
Old 13-08-2018, 03:26 PM
Jon_Bmw Jon_Bmw is offline
Senior Member
 
Join Date: Nov 2007
Posts: 127
Default

That's odd. Almost like a ctrl alt delete windows fix!

I guess I would just check that the dsc is actually working by performing a few emergency starts. Then deactivate it and check that it allows you to burn some rubber.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 07:51 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2018, vBulletin Solutions, Inc.