I have a Jaguar XF Portfolio March 2015 2.2d; after 9 years I still love it and hope to keep it for many years to come but my current issue is driving me potty.

In heavy rain, after an hour or so of driving, I get a loud audible alarm and a message saying "Parking Aid Unavailable". At this point rear camera and front/rear sensors no longer work. They resume working after a dry spell. So I am thinking a water related issue.

I took it to a Jaguar dealer but Sod's Law it was a dry day and the fault was not present although they did find two faults using their diagnostic tool. These did not allow them to identify the actual fault. I have a iCarsoft CR Pro tool and that (when the fault is actually present) gives me the same two errors as per the image below.

As these two faults are front and rear sensors power circuit I am thinking water must be getting in to something common to both modules. My questions are: (1) Is my logic sound? (2) If so what is the common cable/connector that water could be getting in and where should I look?

I have tried listening to the individual sensors but can't hear or feel anything (some say you should be able to hear the sensor when its active).

I am really struggling to find any useful steers in where to look for water ingress as every model/year of XF seems to swap things around. I can do basic mechanic-ing and can use a multimeter.

I would appreciate any help at all please. 

 

 

I would agree with your logic, i'm not wildly familiar with the XF but would imagine it's electrical architecture to be similar to the S Type. There is a general module that's in the boot on the S Type (which could be a clue) and i'm not sure what other modules might be involved. I'd suggest checking in the boot, see if you can find any signs of water ingress/dampness, also check your sunroof drain holes/hoses in cae one or both is leaking water into the boot and causing your problem.

As for hearing ultrasonic sensors, the clue is in the name - ultrasonic. They tend to operate in the 22-40KHz range, most humans can only hear up to ~18kHz so if someone says they can hear it, check them for bat DNA or assume they're mistaken or very lucky.

Good luck with it, let us know how you get on.

Dave thanks for that. I will check behind the trim in the boot for any signs of water ingress shortly.

Well I checked the boot (both sides and spare wheel well) and absolutely no damp or water ingress at all, see pics below.

I understand there are 3 modules for the parking aid system (rear sensors module, front sensors module and master) but I could not see any of them in the boot area, any one any idea where they are? Many thanks.

 

Well I might be premature in updating this thread but...

I never did find the parking sensor control module. Looked in boot, behind LH and RH boot trims, under seats, under bonnet, under dashboard etc. All difficult to access with horrible plastic clips etc.

Jaguar wiring diagrams didn't help as I found many that covered my year of car and all showed the module in different places - why the need to move it around so much? It's as if the installer changed stuff every day on the production line.

However I did notice a small water stain near the junction box (fuse box) rear on the RH side of the boot. I noticed the filler cap water vent pipe was blocked so unblocked it and not had the issue since. Maybe water was somehow getting into the boot and running through the fuse box causing the issue when it rained. Time will tell.