Mercedes W204 rear parking sensor.

[Pedrostar88]

Hi after hooking my Mercedes up to diagnostic machine I have a faulty rear parking sensor number 7 on my W204 C class. Question is how do I find the part number for this sensor? Having looked on eBay etc I see different part numbers and some saying they only work in certain positions? Want to buy the correct one to make sure it is suitable.
Thanks.

 

[alecmascot]

Online EPC

 

[Pedrostar88]

Online EPC

I found it on the attached diagram but it’s the only part number missing from the attached list, any idea why? Bloody typical.

 

[alecmascot]

I seem to recall you can reach the sensor from the back of the bumper and remove it to check the p/n.