Here We Go Again!

[Snoop D]

Yep, you probably guessed it, ANOTHER problem. My car is getting excited for Christmas I think, so it's decided to turn a few warning lights on the dash.

Yellow ABS, yellow triangle traction, yellow tyre pressure indicator, yellow handbrake light (when handbrake is released) and red airbag light have all come on. Tyre pressures are 35 all round on 19's, but the light still doesn't go away. I have pressed the DTC button next to the roof/tyre pressure/heated seats buttons, but still nothing happens. I was driving it yesterday in the wet and was VERY twitchy and kicking its tail out as the traction has permanently been disabled for some reason?

I've heard replacing/cleaning the wheel speed sensors will fix this? How many are there and which ones do I replace?

And obviously no airbags have went off, so I'm confused why this has turned on

The car has had a brand new quality Bosch battery as the car had been sitting off-road on my drive for a few years.

 

[Snoop D]

Funnily enough, the bulb warning light doesn't come up - even although I have non Canbus leds and rear indicator bulb has failed...

 

[tomrdy]

You're not having any luck with this car

Without a fault code reader at the very least its going to be pure guesswork to diagnose (tbh, even with a reader it's like that sometimes anyway!).

From me experience and forum lurking, there's a few things that could be the issue:

- Steering angle sensor (this will trigger traction + handbrake + tyre pressure)
- Wheel speed sensors (this will trigger combinations of the above with ABS I believe)
- Faulty brake pressure sensors (I'm not 100% on this - someone more knowledgeable will jump in)

All of the above are relatively easy to try yourself though I have not done the pressure sensors myself. From my research (when I anticipated needing to do it), if you got fast hands, you can hotswap it without needing to bleed the system again. You just need an appropriate spanner.

Wheel speed sensor cleaning is probably the easiest to try first and it's free (assuming you have basic hand tools). There are 4 in total - one on each corner and it's a piece of cake to remove + clean.

- Follow your usual jacking-up procedure and remove wheel
- Look behind the knuckle (???) and you'll see the sensor. It's attached via an allen key. I would WD40 the bolt up a bit to avoid any additional issues with breaking screws/nuts... with your current luck
- Unscrew the allen and wiggle the sensor out
- Clean it up with an old toothbrush and replace

Look for something like this:



For reference, mine looked like this when I pulled them out and they were still functional without any cleaning as I could verify wheel speed with diagnostics:

 

[Snoop D]

Thanks tomrdy for the swift reply! You've given me help on quite a few things lately and it's greatly appreciated!

I will give the speed sensors a clean up and see how it goes. I will note however that my alignment/tracking is way off - so it could be the steering angle sensor? Anyone know how to replace/clean this?

Thanks.

 

[skelters]

Get the error codes cleared, drive it and see what codes comes back.

It'll probably give you a better idea of what needs done to this car

 

[tomrdy]

I will give the speed sensors a clean up and see how it goes. I will note however that my alignment/tracking is way off - so it could be the steering angle sensor? Anyone know how to replace/clean this?

Tracking being very off could do it as well. You'll need INPA to zero the steering back but best to get the alignment sorted mechanically before doing that. However, if it's your sensor that's buggered, I solved my issue here: https://z4-forum.com/forum/viewtopic.php?f=3&t=116884&p=1680732&hilit=steering+angle#p1680732 .

It's a temp fix but "easy" as it's all done in place. A proper fix is to replace it with a rebuild kit but... well I'll be honest - too lazy for now :roll: Would still need zero'ing/resetting though.

And you're v welcome

 

[firebobby]

In the pas, my tyre pressure light has come on, after checking and finding nothing wrong, I press and hold the tyre button, it has always gone out doing this.