?

[Henry]

What is it. It’s in passenger inner arch

IMG_0302.jpeg (3.2 MiB) Viewed 466 times

[JohnW]

(I must admit I cheated)

Tyre pressure monitoring system antenna/receiver:

https://www.ebay.co.uk/itm/175770982382

[Henry]

Didn’t even know I had that fitted, first job when I come of the jacks will be to let air out of one of the tyres to see if the system works. Must be something similar to the x5 that warns at about 3 psi loss. Are there Alpina only monitors.

[JohnW]

Looks like standard BMW, not Alpina specifically:

https://www.realoem.com/bmw/enUS/showpa ... 6146759023

[JohnW]

How and if that system works with Alpina wheels and those valves together is another question:

As you may have suggested, it seems as soon as the B3 was fitted with Alpina wheels and tyres it became redundant, unless the BMW valves can also fit the Alpina wheels:

https://www.realoem.com/bmw/photos/36146792829

[Henry]

Now that I’m back on the road I let one of the tyres down 10psi and had a drive round the houses. No RDC lights showed up. However when I now run a diagnostics check it shows a fault stored in the RDC module which doesn’t clear. Damm.

[JohnW]

Have you done the diagnostics before? It may have been there previously. Apparently the batteries in the RDC valve stems last around 7 years.

[Henry]

I have done diagnostics before and it definately wasn’t there. I don’t know if there is any sort of sensor in there as the last time the tyres were changed they were done at the same time as a wheel refurb so they went away with old tyres and came beck with a refurb and new tyres.

[JohnW]

If there is no live fault then it may just be a historical fault stored in the module, but you’ve tried with a tyre let down so approaching it logically:

1. The sensors are not there
2. The sensors are present and not working
3. The Receiver module is faulty
4. More than one above.

It could get expensive if it needs changing then a new or used unit coding to the car.

You always have the option of having the module coded out of the vehicle order if you aren’t particularly bothered about keeping the system.

Either way looking further into the problem, it’s going to require someone with dealer level diagnostics to look if there is any more details with the fault, coding in a replacement if it’s a faulty module or coding out the system altogether, which is the way I would go as not many E46s have it anyway, or just leave it as it is.

As a long shot you could try battery disconnection for a few hours again, just in case.