Help needed for a RCDLR diagnosis
I cannot find a thread with my conditions so I thought I would start a new one. I recently tried to get my 2009 C6 out of winter hibernation only to get the honking alarm when I attached the battery (never happened before). None of the buttons on the fob would stop it. After that stopped on its own, I tried to start the car but I was getting the "No Fobs detected" message. The car still made all the same clicking noises as usual. I checked the batteries in my key fobs and they are good. I was able to put a key fob in the glove box slot and start the car.
After a bit of research, I came across posts that said the RCDLR commonly fails, likely due to cold solder joints or blown relays. I took mine out of the car. The connectors and wires all look fine. I re-flowed the solder on all pins from the two connectors used (both sides of the board) and a few others that looked dull or lean. I uses a magnifying glass to ensure they all were done fully and there were no solder bridges/shorts. I also tested and measured all four relays. They are all good, and as I mentioned it makes the same clicking noises it always did.
I plugged it back in and no change. I then found the long auto-learning procedure so I did that. This is the process, in case I got it wrong.
- Turned the physical key in the trunk lock 5 times within 5 seconds.
- Got the "Off/Acc to learn" message
- Pressed the bottom half of the start button and watched it count down from 10 minutes.
- Repeated the same thing two more times.
- Got "Ready for Fob #1" so I put the first fob in the glove box slot.
- After a few seconds, got "Ready for Fob #2". I took out the first fob and put my second fob in the slot.
- After a few seconds, got "Ready for Fob #3". Pressed the bottom half of the start button. The message disappeared and went blank.
I then tried to start the car and still got "No Fobs detected" after the clicking. I tried the acc or on states as well with no change, so I just unplugged the RCDLR and disconnected the car's battery. I realize now that I didn't try pressing any of the buttons on either key fob. I wish I had tried that before disconnecting power again.
Does it still sound like my RCDLR is bad, or could it be something else?
Thanks for your time.








