Steering angle ECU not present / issues with running in wet

[Jon B]

Hi,

I’ve been having intermittent issues with my A6 for about 6 months now. Currently have 100k on the clock.

I’ve had battery replaced, area under scuttle cover cleaned out and I still have issues.

The symptom I am getting is the sensation at motorway speeds of a feeling like the brakes are being applied for a second and then released, but only intermittently and only during/after heavy rain. I also see a significant reduction in fuel economy (circa 10mpg).

It has become apparent since we have had a decent dry spell of weather and the issues went, but came back after heavy rain yesterday/last night.

I’ve rescanned with Carista and there are no codes showing, but consistent throughout is that when scanning the various ECU’s I always see on the “steering angle” - ECU not present.

I’m wondering if there is something strange going on with the ABS/steering system that could be causing ESP to kick in when in cruise control?

I’ve spent a fortune on this and as the issue is hard to replicate on a test drive, many garages are just shrugging their shoulders.

Any advice/views would be welcome.

Cheers

 

[elan2s]

I seem to recall, and I may be wrong and it may not apply to Audi, but some cars have a system where they momentarily apply the brakes in heavy rain to keep the disks and pads free of excess water so that when you need them they work as expected. If Audis do have that feature then it may be that is somehow misfunctioning in your car

 

[Jon B]

It seems you may have identified the cause!

Funnily enough, it co-incides with when I had the front discs and pads replaced. Reading around it seems it is activated when wipers come on.

It’s really annoying! I’ve just had rear pads and discs replaced and it is really pronounced again.

I’m guessing it is applying the function too strongly considering I am noticing it?