2006 mercedes c280 4matic car wont respond to auto door lock key randomly

If the other key works try another battery, if not take it to the dealer.

Check the door lock fuse in the fuse panel... try the key on another door... may just be that the manual lk is malfunctioning on that door... if the other doors don't respond and the fuse is good then the key probably needs to be reprogrammed by the dealer to the door... happens when your battery dies or is replaced.

Sounds like the immobiliser needs to be reset or the key reprogrammed as there is a mismatch somewhere.
A good mechanic or your local Mercedes dealer can sort this out for you

The first thing to do would be to check all fuses. Sometimes a very random blown fuse can cause this. Also unhook the battery for one hour to reset all systems, and try a jump start if you have not just to be sure it isn't a battery issue. Also try locking/unlocking the key driver's door a few times using the key in the door. If the fuses are good and the battery reset does not help, nor a jump or key in the door, then there are a few other things that can cause this such as bad key - try another one, bad brake light switch, the switch is above the brake pedal, shifter not fully in park (auto transmission only) - try moving it around a bit, bad transmission position switch, bad clutch switch, dead starter/solenoid/relay or bad ignition switch/cylinder/start button.

May need to reprogram key to vehicle

When you get the doors unlocked, simply unplug the lock servos (motors) inside the door panels. The locks will still work manually and with the key. If they don't work with the key, then remove the linkage from the servo, to isolate the power lock function from the lock mechanism. Test the key while the door panels are off to avoid having to take them off twice to remove the linkage

sounds like the battery in the remote is old and dead and needs to be replaced. ( could also be the electric door lock fuse ).
if you are also experiencing trouble with your door locks themselves turning - then try and spray some teflon or silicone base lubrication in all the locks to wash out any dirt or debris.

c...

hello,good day,first try to use your spare key,or check your fuse box at the rear,near your battery,if not corrected,send your car to a dealer for proper diagnose by using hht or star,ty

Hi abdumi0f,

Firstly, open your glove box and make sure Valet Mode is not enabled, if it is not, follow these steps.

Step 1: Open drivers door and leave open.
Step 2: Lock and unlock the driver’s door using the power door lock switch on the door.
Step 3: Insert key into the ignition.
Step 4: Turn key to on position and return to off position. (IMPORTANT - use ON position NOT ACC position). Do this 3 times within 10 seconds. Leave key in the ignition.
Step 5: Open and close the driver’s door 3 times. (Door should be left open after this step).
Step 6: ECU should respond by locking and unlocking the doors.
Step 7: Press any button on remote #1 twice. ECU responds by locking and unlocking the car doors.
Step 8: Press any button on remote #2 (etc.) twice. Each time the ECU will respond by locking & unlocking the doors.
Step 9: Remove the key from the ignition and the ECU will respond a final time with a series of door locks and unlocks. You're done!

Hope this helps,

Lazaruselite

hello i have an e- class electric key which maybe the same, if it is :- if you look at your key you will see a rough nobly curve near the silver edge of silver with a hole in it, push the rough bit up, and pull out a sketeton key.