Disappearing fault codes, SRS and Park brake error

[veebs]

Our D4 has a fairly regular 'SRS' warning light come on, and a minute or two later displays a Park Break fault with the associated brake warning light. No 'bong' to indicate anything is wrong, just a visual warning. There is no screeching when the EPB is applied, and it works just fine (ie, holds the car on a hill)

D4.jpg

What makes this all the more irritating, is despite regularly throwing this warning up, there are NO fault codes stored in the computer. The local independent LR expert in Bentley can't find anything... The battery hasn't been disconnected at all, nor has it had any issues starting (like you would expect from losing power)

We even had a total 'meltdown' moment, during the GOE training, where it looked like every system in the book failed. A 'turn it off, wait 10 min and turn it on again' solved that one, though the damn park brake light came back about 20min later. Also nothing about this in the computer...

Has anyone else had either the SRS and park brake warning, or the total lack of fault codes problem?

[IvanR]

When the park brake light comes on, have you tried stopping, engaging the park brake then disengaging it to see if the light goes away.
My park brake fault light has a tendency come on when travelling on very corragated roads. Doing this makes the fault light go away.

Ivan

[veebs]

I have, to no avail. But the fact it only generates the fault after the SRS light leads me to think that the park brake isn't actually malfunctioning at all, and that the error lies upstream, in the SRS system somewhere...

[IvanR]

If the SRS is the main fault then the clock spring could be the cause. Do the buttons on the steering wheel still work??

Ivan

[veebs]

Yep, they are all ok - cruise control etc is fine. Where/what is the clock spring?
I don't understand why the faults would be disappearing?

[LandyAndy]

A "clock spring" is the term for how the steering wheel controls are transmitted to the ECU.
As you can imagine wires cant wrap and unwrap with the steering wheel as it turns.
I doubt its a clock spring issue.More likely a bad connection in the Can Bus system or a bad earth in the same system.
Andrew

[Graeme]

The SRS component could be the seat belt receiver and being in the vicinity of the EPB switch I would check for a loose common earth, possibly under the centre console.

[veebs]

Thanks guys - I'll take a look in the morning. Excited about having a solid clue!
I'm taking the car up to Jurien bay for Easter so any success should become apparent on the long trip up...

[LandyAndy]

If you haven't got a manual,I would suggest you order one.
It seems you are up for checking things.The manual will tell you where all the earths connections are and how to remove items.
They are available thru the website.
https://www.aulro.com/afvb/redirect-...um%2Findex.php
Andrew

[veebs]

Cheers for the link - looks like something that would be right up my alley :-)

Yes, up for checking/upgrading things. Mostly also up for not spending hundreds to have someone else fix what I can!
This is going to be one pampered D4!