[t4ure4n]

I have a 2010 model 520d SE. The car was hit at the rear and the active headrest for driver and passenger side deployed. Both headrests are stuck in forward position and I can't push them back.

I started looking online on how to perform reset.
One of the videos on YT shows that I need to wind the spring back.

What I can't figure out is if I also need to replace the detonators as well. How do I figure out if I need to do that.

I found the part number 1734654 on the Pyrotechnic Detonator for driver side headrest. But I can't seem to find it on online. Any advise where I can buy in UK will be really helpful.

[t4ure4n]

I found repair manual https://www.newtis.info/tisv2/a/en/f...-3234/CkyE4XPe according to this,

Renewal of pyrotechnics may be carried out up to 5 times. Triggering frequency is denoted on the sticker on the head restraint carrier. Labels are available as spare parts.

Does it mean that I can re use the old part without the need to replace it?

[t4ure4n]

I am really struggling here as I am unable to find this pyrotechnics charge part number 1734654 online.

Can someone advise me where can I buy it from?

[sashaeuro]

hi I have the parts your looking for. Let me know.
Thanks SD

[t4ure4n]

Originally Posted by sashaeuro

hi I have the parts your looking for. Let me know.
Thanks SD

Thanks for the offer 🤗
But I ended up going to BMW dealer to get them just before Christmas.

[sashaeuro]

Your very welcome! was the item expensive?

[t4ure4n]

Originally Posted by sashaeuro

Your very welcome! was the item expensive?

I paid around £76 for one
The process for pushing the headrest in place was very hard. It's definitely two person job.

[Roberto0606]

Hi,

I am suffuring from the same issue. Today I have hardly removed the part (Pyrotechnic Detonator 1734654) and will order a new one from dealer tomorrow. Could you please help me by explaining a little how to set the headrest and replaced new part? I really appriciate.

[t4ure4n]

Originally Posted by Roberto0606

Hi,

I am suffuring from the same issue. Today I have hardly removed the part (Pyrotechnic Detonator 1734654) and will order a new one from dealer tomorrow. Could you please help me by explaining a little how to set the headrest and replaced new part? I really appriciate.

What I did was
1) Disconnect the battery

2) open the back cap of headrest. The process to open it depends on the style of your headrest. I opened mine just by pulling with fingers from right+left side.

3) Remove+unplug the old detonator.

4) Wind the circular ring so it fits in place and be able to hold the new detonator. To do this step someone has to push the headrest with massive amount of force from the frontside while you wind the circular ring with tool similar to pliers. Just follow the process as shown the video in my first post.

5) Once it's done plug the detonator and plug the battery.

6) clear fault memory.