madmouse28

I have a w220 s500 and have been experiencing issues with the door/truck locks. It only happens when the car sits for an extended period of time (3+ hrs). It won't open with either of the fobs til I start the car and run it for 15 minutes or so then it will work again. I have checked the batteries in the car and in both fobs. Anyone have any ideas?

lganski

How old is the battery. The systems in the car are very sensitive to the battery supply.

madmouse28

The battery in the trunk is 7 months old , the fob batteries are 3 months. all have been tested and are in the good range.

lganski

Just for grins and giggles clean and reseat the connections to the battery and see what happens. (I mean with a brush, just don't reseat it.) Its a no cost test.

ibeforreal

I'm still thinking the battery. These batteries might show that they are OK but still doesn't have enough power to run everything. I had one go out on me that was about 9 years old. Turned out to be a dead cell in the battery even thought it was testing OK.

If your battery is only 7 months old then it should definitely be under warranty.

madmouse28

Yes that was checked as well.

madmouse28

I'm thinking there's a leak in the pneumatic air lines. It's been pressure tested however the problem only occurs when the car sits for a few hours.

The RF amplifier tested good, the charging system is good, fuse are all good , all the codes were clear, I'm stumped!

deuxslow

Same issue with my 2001 CL w215. If I sync one key by putting it in the ignition my second key will start working. For some reason the car's memory doesn't recognize the key fobs after a couple hours.