key fob

[David Bird]

Went to go out today put fob in ignition and no noise of steering lock releasing and so fob would not start car - Had to go and get spare fob and it worked ok as did the flat non battery fob . Any pointers ? i must assume its nothing to do with the fob battery or why would non battery fob work .

 

[ivandraganov]

Your fob is faulty now,batteries are only for activating the alarm...

 

[grahamcarvlin]

I only got two key fobs with the car. Both battery ones. I'd there meant to be a third one ?

 

[Dec]

Post #3 here… Cost of the flat (spare) key? - MBWorld.org Forums
Master key, it has no buttons or batteries, it will start the car and disable the alarm when it’s put into the ignition, it also has a metal key to open the door/boot.
I think the idea is that you keep it in your wallet so if your regular remote was lost/stolen or failed to work or some part of the central locking failed then this would get you back on the road.

No idea if you should have one for your car that might depend on the year of your car.

Dec

 

[Dec]

Went to go out today put fob in ignition and no noise of steering lock releasing and so fob would not start car - Had to go and get spare fob and it worked ok as did the flat non battery fob . Any pointers ? i must assume its nothing to do with the fob battery or why would non battery fob work .

Is it remote fob type A or B that you have.

Dec

 

[David Bird]

The remote i have is type B , Is there a common reason the fobs stop working ie break in circuitry . Dont fancy going to expense of getting a new fob if cost is likely to be £50 + May have to hope the other normal fob and the flatter version last the course . Thanks for responses thus far guys.

 

[David Bird]

Dec the link you post seems rather unclear - doesnt seem to be any clear explanation.

 

[Dec]

I wanted to see which fob you have. Type B below.

I believe there two possible reasons for the failure of fob type B, either the coil gets damaged in a fall if the key is dropped or there is some sort of memory loss which can be restored for about halve the price of a new key fob from the dealer.
A new key from the dealer is about £225 or thereabouts.

You could try putting the faulty key into the ignition and pressing any button either once or twice, I don’t think this will work but no harm in trying anyway… that’s just something I read somewhere.

You should wait until/if the other key fails, you do have a spare in the form of the flat “Master” key so you won’t be stranded.

Dec

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[David Bird]

Now started using spare fob and strangely when i press unlock it only opens drivers door lock ,found that by pressing twice it then opens all locks . Is this the norm because with the fob that now appears not to work all doors unlocked with one press of fob.

 

[salesac1]

Now started using spare fob and strangely when i press unlock it only opens drivers door lock ,found that by pressing twice it then opens all locks . Is this the norm because with the fob that now appears not to work all doors unlocked with one press of fob.

See explanatory attachment from the owner's manual.

 

[Dec]

As above, or to simplify, you can program the fob by holding down the lock and unlock button, continually for 5 seconds, only drivers door and fuel filler flap will unlock on one press of the unlock button, press again and all doors unlock including boot.

Repeat by reprogramming both buttons again for 5 seconds and all doors/boot unlock on first press of unlock button.

The above won’t have any effect on the fobs ability to start the car.

Dec

 

[David Bird]

You learn something new every day comes to mind . Thanks guys

 

[JohnHansen]

I've had the same thing happen to one of my type A keys. Although I did make a discovery and that is that if I put the key in the ignition slot that will not unlock the steering then press the lock or unlock buttons then the steering lock makes the zip sound and all works fine. So I'm wondering if the problem is that there is an IR transmitter that activates when the key is inserted and that has failed. Good news is my key works again but I have to press the button. There doesn't seem to be a description on any forum that explains the sequence of event that lead to the car starting.

 

[Dec]

It’s a mystery to me too, what you describe doesn’t seem to have worked for David Bird yet it works for you and sometimes for others as well.
There does seem to be something in what you say as there is a “infrared type window” in the centre of the ignition switch which is facing the end of the remote fob when it’s put into the ignition.

Dec