-User-

I bought an E61 525xd 2009 and the remote control of the central locking does not work. There are two keys in the car and nothing happens with both buttons. The car also has a Webasto remote control, and nothing happens with that either, even if the lights on the remote control come on. What has been done:

• The "diversity antenna" above the rear window was replaced by the previous owner in 5/2022. I took it out, looks brand new. Opened the case and the circuit board looked dry and clean.
• I took apart the wiring harness coming into that diversity antenna and it was untouched. All the wires looked good externally. I measured the resistances between the connector coming from the wires to the diversity antenna and the connector near the right rear speaker and the resistance was all ok.
• I disassembled the second key, where there is probably a rechargeable battery, because it is soldered into the circuit board of the key. I measured the voltage and it was approx. 3.1V. The battery read 3V, so it would seem ok for that too.
• Checked all the fuses related to central locking, all ok.
• Measured voltages coming to the diversity antenna connector:
  
  -1 red/white 12.4 V
  
  -2 blue/white 4.6 V
  
  -3 purple/white 12.4 V
  
  -4 blue/yellow 0 V (not connected)
  
  -5 brown 5ohm to ground

I was also able to measure between nr. 2 wire (4,8V) and ground with a led pen, and when I press the buttons on the remote control, the LED flashes slightly. So for me it seems that the information about pressing the button on the remote control comes at least trough the diversity antenna?

Notifications:

• Central lock works from button inside the car.
• Cetral lock does not work if you use the iron key in the drivers door.
• The radio channels work normally, as do all other functions of the tailgate and the lights.
• The car informs when starting that the SOS function is not in use (propably not related to his at all)
• In the car, Professional NAVI "CIC" and does not show the gps location correctly.

Any ideas?

-User-

I finally got access to laptop with INPA. I checked first that no fault codes were in CAS module.

Tested the keys with INPA and both send signal.

Did some surfing and readed values in INPA and while I was playing around with remote key, suddenly the central lock remote control started working. First only door locks worked, then also fuel filler did lock/unlock. And finally after playing with remote key locking and unlocking doors also the turn signal lights started blinking. In the end all worked as normally when using remote control key.

What could have cause this kind of issue? I did buy this car from a private person a few weeks ago and he said that when autumn came and weather got colder the problem started with the central lock remote.

First I thought that maybe some door lock actuator would have cause this but it doesnt explain why the central lock did work normally from the button inside the car.

Any ideas?

spectre6000

You're giving me hope for when I finally get around to poking at mine. Mine is very fickle, and sometimes loses the key en route to places and tries to warn me about shutting down. Works sometimes, doesn't others. Maybe reinitializing the controllers and such will wipe out any errors that have accumulated over 100k miles?

-User-

Suddenly next day it the remote control stopped working again. Then it came back, then died.. It acts a bit weird. My attention is now on the keys if the batteries are just almost dead. That would explain that it works some times and sometimes not.

spectre6000

Boo. For mine, the batteries in the fobs are brand new. Replaced them when I got the car. For your sake, I hope that's all it is (assuming you have the Comfort Access option where the batteries are replaceable, as I understand they're not in the standard key setup), and that the computer side reinitialization theory was ALSO a contributing factor.