My 2 key fobs stopped working at the same time (Not locking or unlocking remotely, nor are the lights flashing when buttons are pressed)
When I tried using the key manually, only the driver's side door locks (The air pump is not receiving a signal to lock the passenger door, glove box, or trunk)
However, when I unlock the driver's door manually, it does unlock the passenger door using the air pump.
Also, all doors lock and unlock correctly when using the interior button.
I've switched out air pump modules with the same result, so it isn't the pump.
Is it possible the defective driver's lock actuator is confusing the system (Not knowing what is locked and unlocked) and therefor has turned off the ability for the fobs to work?
Rob at Needswings believes it's still SCREEM related, but Mercedes Swap Shop is not convinced it is a SCREEM issue.

Thoughts? Should I replace the roughly $160 actuator first before spending $700 + on the SCREEM repair?
Could the security siren be involved somehow in stopping both keys from responding ?

 

SCREEM repair at MSS is much less than $700.00. Have you replaced the FOB batteries?

 

Hi ZERACER,

I've changed the fob batteries and adjusted the contacts to insure the batteries make a good connection.
Both Fobs are showing the red LED when buttons are pushed.
I was referred to a Josh when calling MSS and he did not believe it was SCREEM related, as the car starts and runs great with either fob.
I've also tried the proper method to resync both key fobs with no success. (Press either button twice while in the car, then insert key and turn to the run position)

 

YOu seem to be changing the definition of "Manually" and using the word twice. Very confusing. I can't follow exactly what is going on.

 

I don't see how you thought it was the pump or the module in the pump. Take a look at what is below. We know the BCM and CLP/SSM are working from your post above.
But the door lock and key FOB operate thru the SKREEM. The button on the console is wired to the BCM, the door ajar wiring goes to the CLP/SSM.
I vote "Bad SKREEM". Keep in mind there are TWO halves of the SKREEM, the 1/2 that is powered up all the time to operate door locks (is that fuse blown?) and the other half that powers up with the key to initiate the FOB reading and start sequence. NO ONE can say for sure, and I seldom disagree with Josh or Rob -but I vote "bad skreem".

 

Obviously manually means turning the key by hand. I agree that I am a bit confused as well.
Problems like this are simpler to read when shorter sentences are used like a bullet pattern.
Did this happen all at once or over time?
I did not think that opening the car manually involved the SKREEM at all.
The door can be opened without the door switch connected, nothing else would open or close though.
That is my understanding of the system.
My problem is the opposite of this problem, my dash open/close button does not work, but everything opens and closes manually
or remotely.

 

When I place the key into the driver's door and turn it manually to lock, only the driver's door responds. (The passenger door, glove box, fuel door, and trunk do not lock)

However, when a place the key into the driver's door and manually unlock the door, the passenger door does respond and unlocks.

That is why I'm thinking it's the passenger door lock itself that's the issue.

Perhaps there's a sensor in the door lock actuator that is not detecting when the door is being locked, and therefor not sending that signal onward so the passenger door, glove box, fuel door and trunk also lock.

Thoughts?

 

In that case, have you removed and checked to see the dash button is working properly? (Checking the switch to verify it's making contact when the switch is in the closed position?)

 

The switch is fine, pressing one end gets one voltage and pressing the other gets another voltage. I have forgotten what they were, but it is the different voltage that determines the lock or unlock action.
I checked the switch when I had it out. In fact I have a couple of these switches, all OK.
I think the trouble lies in the wires to the CLP/SSM, that is the pump in the trunk. I have to check the voltage where the wires are visible in the trunk without exposing the pump.
It’s no big deal but it bugs me..

 

I've checked all the fuses in the engine compartment and they are good.

Are there fuses inside the interior compartment that could effect the SKREEM unit's ability to listen and react to the key fobs?

If so, which fuses are these?