scandalxk

Mike, any further thoughts following the investigations described above?

So I checked, and I realise that I have checked that ground stud before. It is fine: I can make the boot courtesy lights come on by earthing them via the stud itself, or via the swages of the other (both brown) cables that are attached to it. It is not clear whether the courtesy lights are actually connected to that stud; the blue and white earth cable from the light unit joins a big bundle of cables containing other blue and white ones, and without a wiring diagram (or the knowledge to understand one!) I don't know where they go, or where they finally earth to ground. This particular ground stud is well above the level of any possible flooding, mounted on the rear bodywork and not on the floor of the compartment. There is another stud, identical but unused, on the floor of the compartment: I guess that may be the one which was prone to corrosion due to flooding, and perhaps that is the reason it is no longer used...? But anyway, the stud is fine so I need to look elsewhere downstream to find the problem.

Thanks, I will do that, and report back. As usual, it may take a few days... Regarding the flooding, exactly that happened to my previous Octavia: shortly after I bought it I noticed that the washer didn't work. Then I noticed that the boot smelled of washer fluid, and I found that the spare wheel was swimming in the stuff, overflowing from the compartment behind the panel - caused by the pipe popping off the coupler, as you described. On my current Scout the coupler is much more substantial - a screw fit, not a push fit - and I am careful to keep the antifreeze strong. However, there are at least two other routes for water to get in. One is through the cabin pressure relief valve, which is a large rectangular rubber flapped valve fitted to the bodywork inside that panel: if it comes adrift, water can get in there. The other is if you leave the tailgate open in the rain, water can drip (in fact flow) off the top left corner of the tailgate, onto the strut, and into the bodywork through the strut fitting, then down into the said compartment. And finally, there is a drain hole near the front of the compartment, which gets blocked with crud. So, overall, not very well designed.

Hi Mike, Just got around to this - sorry for the delay. The boot light feed does indeed show 12V to earth when the cabin interior lights are on. And, lo and behold, the boot light does illuminate when the earth side is earthed. So I understand that the problem is downstream (i.e. down the earth side wiring). I am a bit suspicious of the wiring bundle in the compartment behind the panel on the nearside of the boot, because it has flooded in the past, and all the wiring bundles run along the floor of that compartment. There is nothing visibly wrong with any of them, but I don't really know how to test. And then they just disappear into the bodywork around the wheel arch, on their way to the front of the car. Can you suggest how I might go forward from here? Cheers, scandalxk

Thanks again Mike. I'll try that, but it may take a couple of days before I can get around to it. I'll report back. Thanks again.

Yes, everything else works. Only the reversing sensors and the boot courtesy lights are not working.

Thank you, Mike. I got quite excited about this, because I remembered seeing an earthing point with a couple of wires to it in the same compartment as the parking aid controller, behind the NS panel in the boot. And the courtesy lights in the boot have stopped working too...could they both be connected to the same faulty earth? So I dismantled the panels again, found the earth, disconnected it and cleaned it, checked the cables, reconnected, and tested...with no joy. On the other hand, it started raining hard while I had the panels off, and I noticed that water was pooling inside the body compartment, obviously dripping off the top of the tailgate (which was open while I was working in the boot), and leaking in through one of the rubber bushes near the NS tailgate hinge. That clued me in to the fact that the drain hole in that compartment was blocked, so I cleared it out. At least I achieved something for all the faff of removing the panels. But the reversing sensors and the courtesy lights are still not working.

Update: I finally had some time to look at the problem so I took the side panel off in the boot to look at the wiring, and found a parking aid control box bolted to the NSR wheel arch behind the panel. I found a cheap replacement on Ebay, fitted it, and the sensors worked again. The sensor image on the dash came up, indicating the cone which was just behind the car, and the correct warning tone sounded, indicating to me that the sensors themselves, and the speaker, are working as they should. This happy state of affairs lasted for about two seconds, then the fault returned exactly the same as before: long beep, no sensor image on the dash, image flashed up briefly on disengaging reverse, then nothing for the remainder of the journey. I interpret this as meaning that the system is mostly OK, but there is a fault which is causing the control box to fail. Is this a reasonable conclusion? Any ideas where the fault may be? I'm pretty sure the sensors and the speaker are OK since they worked fine, briefly, when I replaced the control box. Perhaps a short circuit somewhere?

Please report back!

I've been stupidly busy since I added my post on this thread, so I haven't got to the bottom of the problem yet. Looking forward to seeing whether anyone has any ideas now...

Probably not the same problem, since my reversing lights are still working.

Thanks Jamie. I'll look out for that when I can pin it down a bit more.

Thanks Golf-Fiend. But I think it's the same buzzer that is making the warning sound... isn't it? It certainly has the same tone.

Update: the reversing lights do light up when I engage reverse gear. Also, the manual states that the long beep "indicates a system fault. Have the fault rectified by a specialist workshop". 😐

Quikcuff, I'm going to jump in on this topic because mine have stopped working too. Yesterday when I engaged reverse gear for the first time after starting the engine, the sensors gave a long beep (about 3-4 seconds) but nothing appeared on the screen, and the sensors did not work when I reversed. When I disengaged reverse gear, the image of the car flashed up on the screen briefly then disappeared. When I engaged reverse gear again, later in the same journey, nothing happened and the screen remained blank, but once again the image of the car flashed up briefly when I disengaged reverse gear. This sequence is what happens now: a beep on the first time I engage reverse, nothing on the subsequent uses of reverse, and a brief flash of the car image when I disengage reverse. Years ago when I first had the car (2007 Scout) one of the sensors failed but the others kept working. I replaced the failed sensor and it was fine thereafter. So I don't think it is the sensors themselves. I will check today to see whether the reversing lights come on when I reverse, and report back. But if anyone here has any ideas in the meantime, I'd be glad to hear them. Cheers, ScandalXK