Further to my last post, I've dismantled one of the faulty sensors to see what caused the problem in the first place. The thing to note is that these are not user-repairable, they are sealed from manufacture. Water ingress is unlikely to be a problem as the sensors are completely filled with rubberised foam.

As you can see from the picture, the problem would seem to be one of poor quality soldered joints. Nothing you can do about it I suppose. Apologies for the picture quality, my camera doesn't have a manual focus.

HTH.

Cheap fix

New (and welcome) update to the Croma parking sensor issue. I've had further parking sensor problems and am toying with the idea of replacing the control module. I removed it (it lives behind the LH boot trim panel - "simply" remove it..!) with the intention of looking for similar units fitted to other cars.

No matches, however when the car doesn't have a parking sensor module fitted, the warning goes away too. This opens up the possibility that aftermarket kits can be fitted in place of the factory fit jobs - and given that such kits are available on ebay for around £30, that's cheaper than Fiat prices. The only downside is having to remove the boot trim to get to the module, however it's not too far from the little 'pop-out' panel so if you're small-handed and brutal you might be able to unplug the module without removing the panel. If you want a look, the module lives forward of, and slightly below, the pop-out panel.

Hope this helps and saves people money!

Re: Cheap fix

wont body computer still be looking for the control unit unless you do proxy aliment first?

if you go after market you can get a camera n screen kit for £50

Don't know - all I can say is the annoying orange triangle of doom is off and there are no untoward messages on the nanny screen at startup. Any experts out there who can confirm whether the car will 'miss' its PDC module?

Out of interest, I might plug my laptop in and run an ECU scan to see if there are any error codes. I'll post the results later.

Just back from plugging the laptop in, FiatECUScan shows no errors. I've been driving the car for a couple of days / 100 miles so I'd expect any problems to have shown up by now. Looks like the car just thinks it doesn't have parking sensors fitted

I have a faulty left rear parking sensor which I will need to replace. I've read the various threads on here and there are plenty of the compatible BMW sensors for sale on EBAY. I had two questions which I couldn't find answers to elsewhere:

1) How do I get at the sensor without removing the bumper? Is it through the black plastic panel at the back of the boot or by going from underneath the car?
2) What is the best way to match the colour - my car is dark grey

My car is a 55 reg 1.9 auto.

Any help gratefully received. Thanks

Had to replace one of my left ones, used a "BMW" one off E-Bay. I have a silver car and ordered a silver one . When it came it was darker than my car but I `m not that bothered as you dont really notice it unless you look for it.
Fitting it was a pain for my Independent who does all my repairs. The sensor is held in with a click in mechanism and as he was trying to get at it from behind the bumper he broke the carrier. He fitted the new sensor into the carrier with waterproof glue. It works fine.

I have an intermittent sensor fault on mine. The strange thing is that it's often on start up, before I've touched any gears. The triangle appears and the message says 'parking assistance not available'. Sometimes I can drive for miles with the triangle illuminated, put it into reverse to park up and the warning disappears and the sensors start working!! :bang:
This leads me to the conclusion that it might be the module that's faulty.

Any tips on how to check what is at fault? If it is the sensor, how do you find out which one is faulty?

halilson said:

I have an intermittent sensor fault on mine. The strange thing is that it's often on start up, before I've touched any gears. The triangle appears and the message says 'parking assistance not available'. Sometimes I can drive for miles with the triangle illuminated, put it into reverse to park up and the warning disappears and the sensors start working!! :bang:
This leads me to the conclusion that it might be the module that's faulty.

Any tips on how to check what is at fault? If it is the sensor, how do you find out which one is faulty?

Click to expand...

This was exactly what happened to mine, my Indi mechanic had a laptop and was able to get a read out that it was the inner left. Not sure if EUscan will give you the same amount of info as I have not used it.
I would be very shocked if it turned out to be the module, its well away from any harsh environment whereas the sensors / connectors are right in the firing line.

halilson said:

Any tips on how to check what is at fault? If it is the sensor, how do you find out which one is faulty?

Click to expand...

I just plugged in multiecuscan and got the code C1002 Rear left internal sensor (see screenshot attached) but now I come to think about it a bit more I'm confused about the word "internal". It might just be imperfect translation though.

stuart543 said:

I just plugged in multiecuscan and got the code C1002 Rear left internal sensor (see screenshot attached) but now I come to think about it a bit more I'm confused about the word "internal". It might just be imperfect translation though.

Click to expand...

I would assume that it means the 2nd in from the left. Do you have the full paid multiscan (mine has just expired) and did you connect to the main ECU or to the body ECU?

halilson said:

I would assume that it means the 2nd in from the left. Do you have the full paid multiscan (mine has just expired) and did you connect to the main ECU or to the body ECU?

Click to expand...

Yes, you must be right - obvious now you've said it, but it didn't occur to me! I have the fully paid version. I think it was the body ECU, but to be honest I can't remember, and my laptop is at work so I can't open it up and check. I definately had to go to a different menu to the one I normally use, e.g for checking the DPF.

Noticed a faulty parking sensor on Croma 1.9 Diesel 2008. Placed a plastic bucket on a crate in front of each sensor, one by one. Found the second from left to be broken. Connected FES and got the same result (second from left). No warming on the dash board.
Ordered a new one from Ebay, p/n 735393479, black, about 15 euro, all in. Was able to replace the sensor without dismounting the bumper, no towhook fitted. Painted it in the correct colour after testing.