I've had this issue with my X350 since I bought it, and as it doesn't bother me much, I decided to live with it until I was sure the car was a "good one" and I was happy to spend money on it. The car's been doing 700 miles per week without fault, so I figure I may as well try to sort this now.

The issue is that both keys work fine on the first press. For example, I can leave the car overnight, unlock it in the morning with the remote unlock, drive a couple of hours to uni, and lock it with the remote lock, with no problems at all. However, if I want to unlock the car with the remote lock, and then lock it a few minutes later with the remote lock, or perhaps use the remote to unlock the boot, it won't work - only the first press of the key works.

This applies to both keys, and I've followed the instructions for pairing them with the car, which hasn't made any difference. They pair successfully - I get the right beeps etc, but the issue remains. I've taken apart both keys and replaced the batteries, and tbh the circuitry doesn't look in very good condition, but surely if it was something to do with the key, both of them wouldn't exhibit the same issue.

So, has anyone experienced this issue before, and any suggestions for how I go about troubleshooting it?

Thanks

 

I am having exactly the same problem. did you get to the bottom of it. I suspect either a bad earth or drivers door module. Any advice on your experience will be appreciated. Regards Terry

 

This is a long shot but if the key circuitry is dirty try using electrical cleaner to clean it thoroughly.

Both my key fobs were filthy and thats what I did when changing batteries.

 

There's a guy on Ebay called Fingas or something like that and he has a great reputation for repairing these things. Might be worth looking him up.
Good luck

 

Thanks for the replies. The fobs are OK, they pair with the system no problem. Other things I have checked are

Car Battery - OK 12.7V
Voltage from Battery to all earth points in Boot (Trunk) all 12.7 Volts
New button batteries in fobs

The main symptom is that the remote works fine on 1st button push, Then nothing. 15 minutes later (or so) fobs work again on 1st button push then nothing again.

I am suspecting an earth problem somewhere else or dud driver door control unit ? But need to be sure before I try hunting one down on Ebay
Rgds
Terry

 

DDM is the common factor but you have to replace get the right iteration and will

probably need to program to the vehicle.

Personally I would just have a look at the DDM ie what are the connections like,

What does the pcb look like, any evidence of dampness etc.

After reading this forum recently I would shy away from reprogramming with SDD.

ie a clone.

 

SOLVED

I removed the door panel and unplugged all 3 connectors on the DDM. They appeared to be OK, clean and no evidence of water or corrosion, but I simply made and broke the connections a couple of times, and the remotes all worked perfectly again.

I guess I would put it down to a slight poor connection on one of the pins. It may also have just presented itself due to a long wet period we have had over the last week.

End result is that the connections were not being perfectly made in the plugs.

Thanks to all who responded with suggestions.

PS I have just noticed Merion's post above after I got the problem solved, but thanks anyways.
Rgds
Terry

 

There's your answer Mr geekman.

 

Thanks everyone. My problem actually appears to be temperature related.

If I disconnect the battery and reconnect it, it solves it for a day or so, but as soon as the temperature drops, the problem reoccurs. Since I have moved to a warmer climate, there have been no problems at all - both keys work 100% of the time.

Nonetheless, I'd be interested to have a look at the DDM. Does anyone have any pictures of how to access it?

 

Hi Geekman. The DDM is under the drivers door trim. Only 3 screws to remove, and don't forget that there is also one at bottom of the trim (screwhead facing to the road) that only needs to be loosened (it loosens one of the plastic clips) and once you disconnect all the other push-in clips you drop the trim rather than levering out (If you try levering that bottom centre one you will snap it off). The DDM is clearly visible as the black box with 3 plugs and "Driver Door Module" written on it. Rgds Terry