E61 LCI Remote Keys Not Working

[robbieduncan]

Looking for anything else I should check before shelling out £250 on a new diversity antenna amplifier.

I have a 07 525d Touring. It does not have comfort access. About a month ago both remote fobs refused to open the car. After opening it with they physical key (which caused the alarm to sound) both keys started working again. But only for a few days. Around this time we also started suffering poor reception on FM.

Looking into the likely causes I have done the following:

1) Not changed the batteries in the key fobs as this only applies if you have comfort access
2) Checked the fuses (59. 77, 79 as these are all mentioned online): all are OK
3) Removed the boot spoiler to check the cabling and have a look at the amplifier: cables look OK, amplifier appears dry

So before I order a new amplifier is there anything else to check?

[helix402]

You can remove and check the diversity module to confirm your thoughts before buying one. If it’s full of water/circuit board corroded your thoughts will be confirmed.

[ladderino]

Could also be wires in the rear wiring loom wearing out as they can get pinched when the boot shuts.

I had this issue on my E91 and looks like the E61 is similarly affected:
https://www.bimmerfest.com/forums/attachment.php?a...

[C0ffin D0dger]

It was the diversity thingy on mine when they stopped working. Not water logged but clearly had a burnt out component on it.

[robbieduncan]

Quick update. £250 on a new diversity antenna amplifier on eBay. Arrived and fitted. Remote keys work again and radio reception seems better. Had a look at the old amplifier I took out of the car. No obvious rust, water ingress or burnt out components but clearly it was the issue. Nice to have a reasonably quick and simple fix!