A209 CLK remote locking inoperable

[Flyinspanner]

Yesterday our 2005 CLK convertible wouldn’t respond to either of the 2 remote keys.
neither doors nor boot.

open door with key blade and car starts fine.

doors will lock/unlock from dashboard buttons.

the 3 fuses listed for central locking are all ok.

tried new fob batteries.

charged the main battery overnight but to no avail.

Has anyone suffered this? Will it be a receiver? If so, where is it located and does the unit have to be coded to the car if Ivan get a replacement?

Are there any steps I’ve missed checking?
Edit

 

[Flyinspanner]

Does anyone know if the IR in drivers door handle if the only receiver?

any schematics?

 

[Trickythemerc]

The IR in the door lock doesn't play any part in the central locking. The CL uses an RF signal. You will probably find the IR receiver is shot anyway, most suffer from dry joints on the PCB.

 

[55AMGCLK]

Have a read of the article below, it has a sync procedure in it that may help, else you will need to get the codes read.

Mercedes Key Fob Not Working – MB Medic

www.mercedesmedic.com

 

[Flyinspanner]

Update.

All fixed

Fuse 8 in the boot, not listed as part of central locking, but it feeds the RF receiver/amp.

 

[Emble9801]

The w209 ir receiver does play part in the central locking as its part of the convenience opening either doors sunroof or the cabriolet hood The rf receiver uses radio frequencies in the cabriolet there located in the front left and right amplifiers and rf receivers connected to the windscreen the ir sensor in the door is a common failure in this particular model w203-209 the only way to test is check via star for voltage from the ir sensor or fix it lots on you tube how to fix them but I ordered second hand door barrels with ir receivers and simply swapped them over the rf signal is fused in the rear Sam if you have Bose or kardamon amplifier then the fuse is connected to that it is a long drawn out process if the amplifiers have gone removal is costly hence using the ir method is an cheaper option hope this helps