Strange key/central locking issue
 

Hey guys and gals, I have an issue with my 03 e53 that has me scratching my head. A little history, bought the x used and only got the 1 key and at some point the drivers door lock cylinder has bee replaced with a blank, thus keyless entry is the only option. Ok, so a month back the wife calls and says she's stuck at work the x won't open, key is doing nothing. I head over and sure enough nothing... I get in through the pass door using an air bag and a flex tool to hit the button and pull the handle twice. The alarm goes off but stops when the key is inserted and started. Drive the x home and start investigating, diamond key buttons do nothing, central locking button does nothing, everything else works as it should (dome lights, wipers, rear hatch button,seat functions) I decide to disconnect the batt for 10 min and reconnect. Magically the central lock system is working as it should! But the key buttons still do nothing. I follow the key reprogram procedure I found on this forum and everything is back to normal. :dunno: don't know what, how or why but it's all good. Now, fast forward to yesterday... Exact same thing! Same call from the wife :( x5 parked in the same spot at her work and same procedure is required for me to fix (apparently temporarily). Any of u brilliant bmw experts have any advice? These parts get expensive fast and frankly I'm getting pretty tired of spending money on this ride.

Thanks in advance, Chad.

Did I miss something in your original post??? What did you replace??? I only read where you disconnected the battery for 10 minutes and everything work again.

Order a spare key for your X or order a new door cylinder for the driver side door and replace the blank.

I Didn't replace any part of the locking/keyless entry system, the battery disconnect "reset" worked. I have ordered a new lock cylinder and key to gain an entry point if this continues to happen but that is just skirting around the problem. My first thought is the gm3 module but disconnecting the battery shouldn't have any impact if it is a module problem... I don't think

In the 6 month of ownership I have replaced,
-Transmission/ torque converter
-ccv valve and piping
-valley pan gasket
-water pump and crossover pipe gaskets
-upper timing cover gaskets
-valve cover gaskets
-rear airbags
-lower control arms
-lower oil pan gasket
-timing chain tensioner
-power seat module
-pre cat o2 sensors
-belt tensioner and idler pulleys
I can do all the work myself in my own shop so labour is free but the x5 is becoming hard to love....

Using the key button and/or central locking button

If the lock/unlock issue happening on a single door - maybe the door actuator.

If the lock/unlock issue happening ONLY on the rear doors - maybe the General Module / Body Module.

Or other that I am not yet familiar with..........................


It is very strange that you key is getting out of synch. The only time our key gets out of synch is when we don't use it for 8-12 months (This happened to us once, never again! I see to it that me+wifey always swap the designate keys every week on our vehicles)

It sounds to me like the battery in the diamond key is on its way out. After you did the relearn/reprogram procedure it had just enough juice to last for a little bit and then couldn't transmit anymore again.

Just my guess though based on experience with e46's. My X came with a key that had a dead battery so I just replaced the battery... relearn procedure... and everything has been good since. Also recommend buying a second key. Our dealer charged $183 for a new one.

I'm going to visit the stealer and look into getting a second key for sure. Do the keys typically need to be re learned after a battery disconnect ? Could the central locking system becoming inactive be a result of the alarm going off? Some sort of security thing?

The first thing I'd do is order a door lock cylinder for the driver's door based on your X5's VIN so that you have a manual way into the vehicle.

If you only have one key...then yes get another one, too. The "coded" cylinder doesn't cost that much and will come already keyed to work with your X. I'm not sure why anyone would replace the cylinder with a "blank" other than to fix/mask a problem...which may be part and parcel to the infrequent remote unlock issue you've now experienced twice.

Also check locally for a place that can check the radio frequency or operation of your key to see if the battery voltage is dropping. One of the things I loved about the old style key is its red LED status light which not only indicated if a signal was sent but also if the battery was dying.

Although the image below is of the old style key and it has an easy replaceable battery you can pick up anywhere...the battery voltage info applies to the new style key...so if you can find an auto store that can check your key's battery...if the voltage is dropping below 2.2 volts...then that could be the issue:

http://bimmerboard.com/members/q/ori...tus%20Info.jpg