745li comfort access not locking

Hello,

Can someone help me out?

I can unlock the doors with key fob in pocket and "pulling" on door handle. But when i go to lock it by pushing in the door handle , nothing happens.

This is something recent. I feel i should also mention that i just changed the battery and this started to happen not too long ago.

Thanks for any help guys!!!

I also wanted to add that i was out of town for about 5 days and the car didnt run.

Probably needs to be reprogrammed.

First follow the remote re-sync process (rarely helps but costs nothing);

To sync a remote key to the car;

1) Close the door, and fasten your seatbelt.
2) Insert the key into the slot in the steering column.
3) Hold down the unlock button on the dash-- don't press the brake pedal --
4) Whilst holding the unlock button press the engine start/stop button to turn on the "ignition on" position. This is when all of the dash indicators come on. Continue holding unlock button.
5) After about 10 seconds the "gong" will sound. At this point you can release the lock button and remove the key from the ignition.
6) Lock the car using the buttons on the key fob and let the car go to sleep (up to 20 mins - the seat control lights will extinguish).

Next, check if any of the door handles feel slightly warm in any place. If they do, the comfort access system has shorted in that handle and it needs replacing (I am having to change one of mine - they are VERY expensive - £400 UK fitted).

If you still dont get any joy, you need a BMW dealer to run a full diagnostic check on the Comfort Access system (UK cost £100). This will tell you what is wrong and the cost.

Unfortunately, Comfort Access seems to be an extremely unreliable system, with failed door handles being extremely common and extremely expensive to fix.

Check the fuses in both boxes. The one in the trunk and the one in the glove box.

Just reset the CA system, that's all you have to do. As for the door handle getting warm ....... was it a hot day? The door handle is just a passive antenna, nothing more, there are no electronics in the handle nor is there anything to program in the door handle, it's just a passive antenna. The control unit for the door handle is in the bottom of the door, the door module and it is what operates everything to do with the door, windows, mirror, lock etc, so I don't see how heat comes up to the door handle.

Initialising Comfort Access control unit and outside door handles

After replacement of the Comfort Access control unit or an outside door handle, initialisation must be carried out. The initialisation is triggered by switching terminal 0 to terminal R. When terminal R is switched, the Car Access control unit transmits the initialisation automatically to the Comfort Access control unit and this in turn transmits to the outside door handles. There is also the possibility to initialise the control units using a test module: Diagnostic heads / Service functions / Comfort Access / Initialisation. The initialisation can be checked in this test module.

Originally Posted by AceFX

Just reset the CA system, that's all you have to do. As for the door handle getting warm ....... was it a hot day? The door handle is just a passive antenna, nothing more, there are no electronics in the handle nor is there anything to program in the door handle, it's just a passive antenna. The control unit for the door handle is in the bottom of the door, the door module and it is what operates everything to do with the door, windows, mirror, lock etc, so I don't see how heat comes up to the door handle.

You are incorrect I'm afraid.

A common fault with comfort access is a 'shorting' of the door handle control which is indicated by a warm door handle as the short is putting a drain on the battery.

When I got my 750i Sport (with a comfort access fault), several members on this (and other) forums informed me of this fact and I checked the car and found that the drivers door handle (only) was indeed slightly warm (it's winter here and the outside temperature was around freezing!)

A diagnostic check at my BMW dealer confirmed this exactly I.e. "fault with drivers door handle causing battery drain, further confirmed by warm handle".

Your second post regarding resetting the comfort access makes no sense whatsoever to anyone who is not an auto engineer, electrician or extremely technically minded. *Is this something that a person with no technical knowledge can do? If so, can you explain in plain English?

Im getting tired of this car and ots not even 1 yr i have it!!!

But thanks guys for the posts!

Originally Posted by Silkyjohnson

Im getting tired of this car and ots not even 1 yr i have it!!!

If comfort access not locking the door is your only problem then you've been lucky. How many cars have you had with comfort access in the past? If you chase problems with these value added features without warranty then you will drive yourself crazy.

Happy to receive your rebuke. If I am wrong, sorry. An antenna is a dead short though. A wire goes in, a wire comes out, it's a wire loop. I have not heard of this fault before. I am in the process of retrofitting CA to my car and I am looking at one of the door handles and I can see no electronics on it at all, just a plug to connect the 'antenna' which is the chrome strip on the handle. I must research this further then to learn what electronics are hidden in the handle. Thanks for the tip.

Originally Posted by AceFX

Happy to receive your rebuke. If I am wrong, sorry. An antenna is a dead short though. A wire goes in, a wire comes out, it's a wire loop. I have not heard of this fault before. I am in the process of retrofitting CA to my car and I am looking at one one the door handles and I can see no electronics on it at all, just a plug to connect the 'antenna' which is the chrome strip on the handle. I must research this further then to learn what electronics are hidden in the handle. Thanks for the tip.

I am no expert, but gleaned this info from several respondents, including this from a BMW engineer;

"Common cause - is cracked and corroded circuit boards inside the exterior door handles. The problems occur at the soldered joints where wire is attached to the circuit board. The result can be a 'shorting' which then places a drain on the battery and an indication of this can be warm door handles."

Hope this helps.

Ta ...... I have all the pieces on the table in front of me and I am looking hard at the door handles.

You need to change the battery after registration

You need to register the battery by


http://www.bimmerfest.com/forums/sho...d.php?t=644567