No reset is required. When i replaced my damaged pdc which was the front drivers corner all i did was remove the front bumper which isnt to difficult and there are guides on the forum. Then replace the damaged pdc with the new one and the system was all back up and running. I am pretty sure that you still need to take the bumper off to get to the middle ones.

ok, i bought a sensor, then when taking off the front bumb it turned out that the sensor housing cable is cut off!!!!!!!!!!! what how did this happen!!!!!!!!!! connected the cables and the original sensor works back normal now!! damn...

If anyone ever needs a PDC sensor for the front of their X5 I have an extra that I would be willing to sell.Send PM if ever interested.

Tips to fix PDC problem
 

This is an overview of all I did to fix the PDC.
1. Clean them of any wax.
2. Lsiten to see which one is dead.
3. Tap the one that is dead to see if it is a contact error.
4. Rear PDC is fiddly but fixable.
5. Look carefully at Inernet pictures so you know where the PDC clips are.
You will be working blind.
5. Use silicon spray to help get them out. You need three hands; two to hold back the clips and one to push out the PDC.
6. You can replace the front center PDC without removing the bumper by doing this: ( it takes 40Mins so calculate that against bumper removal )
6a. Remove the tow hook cover to the outside of the PDC.
6b. Remove the number plate. Make sure you have the plate mounted with this: 51118403075 [Google Images]
6c. Scratch a marking where the plate holder was
6d. Drill three 2.5 cm holes next to each other at the upper right corner of the plate holder for the right PDC ( left for left PDC ). Leave enough space so that the plate holder sits after doing this!!! That is what the scratch is for.
6e. Use a half circle vibe saw [ Google images: "bosch pmf180e" ] to make a neat oblong hole with round edges at the ends from the holes.
6f. Scratch out the sytrofoam behind the bumper to get at the PDC with your fingers. Be careful, I hit the wires with the chisel!!!!
6g. The advantage of this way is you can still drive while waiting for a new PDC to arrive and next time it breaks the fix takes 5 Mins.
7. SWAP the PDC with a good one from the rear to make sure you have not just had a bad contact.
8. If bad get a repalement from eBay.
9. Test.

hi all, after about 4 years of the PDC system not working (DIS5.7 and INPA show all 8 sensors have a bad negative somewhere), I decided to grab a used one from a pick-n-pull yard.
My x5 had a PDC which ends in part number 42676 and has hardware 2, sw 1.7.
The donor PDC is an older part number (21414) but has all the same specs written on outside of box.
NOW the system actually works...sort of.
The rear sensors seem to work fine but the fronts are buggy and go off a lot with no real reason (tho i do believe about 6 years ago, I replaced a sensor with one from an e39, so perhaps its not fully compatiable).
The green light stays on solid now (instead of flashing and constant tone) and it seems to be somewhat responsive to objects. WOOHOO

I was wondering if anyone has ever installed a newer (from X3 LCI) PDC module which also has HW3, SW 2.4 on outside of module?

It says it supersedes the original X5 PDC modules and was just curious if I'm better off finding new hardware/software instead of playing with/coding out something that's just not as great as it could be anyhow (too late, I spent 5 mins and coded off front wonky sensors).

I'm curious why there are SO MANY different parts that were sold as the PDC module. Some lasted a week before a new module replaced it. holy crap.

I don't care for the front sensors, so I just used NCSexpert to code them off.