Hello!

I've had a read through the forum search results and also the threads which were autosuggested from my title with no joy.

My girlfriends 2010 1.4 Lounge 500C has the factory fitted rear parking sensors. When the car starts, the dash pops up with 'Rear parking sensor unavailable' or words to that effect at least.

The electric mirrors are still working, and as the 500C's parking sensor is on the same fuse, I presume the fuse is ok. To be sure I did a resistance check with a multimeter and it was reading 0.07 Ohms which again seems to suggest the fuse is ok.

At the moment it doesn't make any noise in reverse however not long before, it made a constant beep as if there was something in it's way. I'm edging towards it being a faulty parking sensor controller, and it seems as though I can pick one of those up for pretty cheap (around £50-£70 on fleabay).

My challenge is ... I have no idea where it is in the car! I've just traced the cables up from under the rear bumper, lifted the carpet and it looks like the wiring loom then goes towards the front of the car.

Has anyone replaced one of these before and could maybe offer some advice on where the bloody thing is?

Found a repair manual for the 500 online (won't share the location directly but google for 'Fiat_500_2013_Repair_Manual.pdf' its a huge document, over 8000 pages long but after poring through it for a while, I found this:

Hm!

So according to the manual (granted this is the 2013 non-Convertible, but you'd think it'd be pretty similar?)

It should be here: imgur.[com]/a/Gy1c5yJ (remove brackets)

Checked behind both panels in the 500C and no dice. Must be hidden somewhere else.

For anyone still reading ... the parking sensor control module on the pre-2013 models, is inside the boot - on the right hand side, behind the carpet inlay.

I think it’s more likely to be one sensor failed.

Select reverse gear, then get out and put your ear against each sensor - you should hear a clicking sound - the one that doesn’t click is faulty.

If the car is a Dualogic or Abarth MTA, it will disengage reverse shortly after opening the door, so you’ll need to trick it by closing the door latch with a screwdriver etc. while the door is actually open so you can get out.

-Alex

alexGS said:

I think it’s more likely to be one sensor failed.

Select reverse gear, then get out and put your ear against each sensor - you should hear a clicking sound - the one that doesn’t click is faulty.

If the car is a Dualogic or Abarth MTA, it will disengage reverse shortly after opening the door, so you’ll need to trick it by closing the door latch with a screwdriver etc. while the door is actually open so you can get out.

-Alex

Click to expand...

Yeah that does seem to be the most common / obvious cause, unfortunately however when the cars in Reverse there is no clicking noise from any of the sensors - it seems unlikely that all of them have failed ... but it is a Fiat. I've held off on buying a replacement sensor unit at this point as I was waiting for an ELM cable to turn up so I could use multiecuscan.

It returned the DTC of C100D-14 which is making me wonder if I'm going to be going on a bit of a wild goose chase to figure out which part of the circuit is buggered. I'm presuming it's not the fuse because it also runs the electric door mirrors which are working OK.

Every days a learning day