I have a factory fitted tow ball and electrics on my S3.

I connect the electrics to my bike carrier and the rear sensors and blind spot monitor disable which is normal.

However, when I disconnect the sensors and blind spot monitor remain disabled.

Is this normal or do I have a problem?

Everything should turn back on once you unplug the lights, it certainly does in my Superb II, though I don't have blind spot monitoring. The blind spot monitor, at least theoretically, shouldn't need to be disabled because you have a trailer. Check whether you can turn it back on in the setup menus just in case it was turned off at some point previously and you only spotted it after trying the trailer plug. The rear sensors not coming back on is definitely not right though.

Definitely not normal Phil - my retro fit one switches the sensors back on once disconnected, so it would appear something it wrong.

Are people confusing rear parking sensors with the various assistants?

 

After I've unhitched the caravan I have to turn back on the blind spot and the other assist option (memory fails me at this point as to which one; rear assist maybe?).  I don't have to do anything with the parking sensors.

 

@psycholist - the blind spot detection uses radars in the rear bumper so has to be turned off otherwise it will always detect the thing being towed (yup, I know that the OP has a biker carrier).

 

I've never tried turning either back on when hitched up though the amber "it's all been disabled#!*!" warning always scares the bejeebus out of me when I first pull away  :notme:

So unclerichy you too have to manually reset the sensors just like me?

If they haven't automatically turned back on after unplugging the bike carrier then I'm assuming they haven't worked since?

So unclerichy you too have to manually reset the sensors just like me?

 

Nope.

 

For example...

 

• Nothing hitched up. Car in reverse - guidance lines in rear view camera and nice beeps as I reverse close to something.

 

• Hitch caravan up and plug in 13 pin cable. Car in reverse - picture of my caravan in rear view camera, no guidance lines and no beeps as I reverse.  Pull forwards and warning flashes up telling me that blind spot detection and (I think) rear traffic assist have been disabled.  Cars either side of me don't cause the little symbols to appear in my wing mirrors.

 

• Unhitch and remove 13 pin cable. Car in reverse - guidance lines reappear and the beeps are back as I reverse towards something.  The blind spot assist and t'other assist are still disabled and I have to turn those on manually.

 

If you're saying that your reversing sensors stop working after you've unplugged your bike carrier then something is amiss; though you don't say how you get them to turn back on again (as silver1011 alludes to).

 

If it's just the two assists (activated from the Maxidot screen/vibrating car button on the steering wheel) then I suspect that's normal behaviour.  The fact that the car disables them when it spots a 13 pin connection but then doesn't re-enable them when you disconnect is rather daft, mind you.

The sensors remain unticked in the maxi dot after disconnecting the towing electrics.

I have to manually reset them.

The sensors remain unticked in the maxi dot after disconnecting the towing electrics.

I have to manually reset them.

 

Yes I have to do the same, a bit annoying really.

I recall having to re-enable blind spot monitoring last time I unplugged my towbar-mounted bike carrier too.