Remote Key Problem

[platnm]

The remote key for my C240 (2001) is playing up.

It suddenly stopped working a couple of weeks ago; so I changed the battery (the same as before CR2025 3V X 2). now it sometimes works and sometimes I have to use the emergency key to open/lock the car (it is not consistent); I tried to use the spare key as well and the same problem. eg the remote won't work; lock the car manually; go to the shop; come back and 5 out of 10 the remote will not work.

When I press the key the red light in the corner comes up once;

Any idea?

THANKS.[/b]

 

[maddog]

I recently had my key fob replaced under warranty because it was demonstrating those symptoms.

 

[joe bloggs]

Does it work when pointing directly at door lock (small square window). as this remote sends both an infra red (as above) and a radio (non directional) signal, your radio signal may be missing and at the times when you get it to work you may be pointing the infra red signal at the door lock. The infra red part also should close the elec windows when the lock button is held down.

 

[platnm]

Does it work when pointing directly at door lock (small square window). as this remote sends both an infra red (as above) and a radio (non directional) signal, your radio signal may be missing and at the times when you get it to work you may be pointing the infra red signal at the door lock. The infra red part also should close the elec windows when the lock button is held down.

Thanks for the reply.

No; if it doesn't work them it does not matter where you point at or how close you are to the car; and if it is working it works from eg 10 meters away! it is unpredictable!

 

[molar]

mmm, my ML320 has similar problems.

It can work wonderfully, but occasionally I cannot lock or unlock with the remote key fob. I need to open using the key (which sets the alarm off) then re-synchronise.

i.e Turn to ignition position 2
Back to position 0.
Remove key.
Press and hold lock butonn
Then press unlock button 5 times.

It will fix the problem immediately. It can then work properly for a long time...or it can go faulty again after a few presses.

Is it the Alarm system or the key fob?? It happens to both my key fobs.

 

[Andy]

Hi


Unfortuanately Molar your ML is different to the C240. The ML is Das 2x & the C240 is Das 3. Which means the ML has a flip out key the c class has a plastic key.

The plastic key uses to forms radio signal to open the door. Infa red when close to the vehicle & radio waves when further away (as I presently understand it.) I would suggest the key is faulty & you replace the key. These keys can be problamatic, especially if dropped. The keys are about £60. But come codded to the vehicle. You WILLL need your log book to order from you local stealership.

If there is the slightest doubt about the key either check with spare or replace. No other cheap way.



Regards


Andy@ www.mercedesservicing.com

 

[molar]

Thanks Andy

I have booked my ML in to get the alarm and the AC checked (AC not cold!).

I do hope it is the key fobs as opposed to the alarm system.

 

[molar]

AC fixed. Needed "re-gassed" which I guess is something like topping up the refrigerant.

Both key fobs are fixed. After running the diagnostic software they found FIVE faults!:

1. Code B1783: CL signal contact Driver's door supplies implausible values- fault during unlocking

2. As above- but fault during locking

3. B1703- Programmed code of the transponder is invalid.

4. B1040- CAN bus: fault in communication: ICM

5. B1784- CL signal contact passenger door supplies implausible values- Fault during locking

Don't really understand any of it, but the dealer assures me that the Fobs are fixed and do not need new fobs!

So I will need to try them for the next few days and see what happens!

 

[molar]

mmm, so the fobs were fixed on Monday. Today is Thursday and they have started playing up again!!!

Will phone Vardy (Glasgow) tomorrow to let them know and see what they say!

Not a happy chappy!!!