rtreyna

I have a 2010 528i that I have been having a problem with. Bare with me as it will take a little while to explain.
The issue started about a year ago when my key fobs stopped working. I believe one stopped working a few months before the other one but it has been so long I cant be 100% sure. Not looking forward to paying the $300+ each for new fobs I resorted to just using the manual key that slides out of the fob to lock and unlock the car.
The manual key would lock and unlock the driver door with a single turn and lock and unlock all doors as well as arm and disarm the alarm with a double turn.
Fast forward a few months and the manual key will still unlock the driver door but will no longer lock and unlock all doors with a double turn. Also will not arm or disarm the alarm when locking and unlocking the driver door. No more alarm chirp and no more blinking red light under rear view mirror.
Now every time I unlock the car I can only unlock the driver door and have to unlock the rest of the doors with the door lock button on the dash. And only way to lock all the doors is to sit in the car with all the doors closed and lock the doors with button on the dash(which also used to arm the alarm with all doors shut) and then open driver door, get out and manually lock the driver door.
I grew tired of this as well as not having an alarm anymore so I decided to order a new battery for one of the fobs. I got the new battery and tested it out of the box and it was putting out 2.97 volts . So I cut open one of my fobs and soldered in the new battery and crossed my fingers.
Still nothing. I also attempted to reprogram the fob following several procedures to no avail. I don't believe you have to reprogram a fob if its one of your existing fobs already.
I have heard of the diversity antenna going bad from moisture and corrosion due to its location and causing some of these issues. So I removed the diversity antenna and it doesn’t look like any moisture had gotten to it and no corrosion to be found. Also my FM/AM signal is still very good. So I cleaned up all the contact points with electrical contact cleaner on antenna and rear window just for good measure and reinstalled. No changes.
I have also went through almost every fuse in glove compartment and trunk to make sure none of them were blown. Trunk and Hood sensors both seem to be in good working order. Tested them both separately by leaving them open for a while and then closing. Upon closing you can hear an audible noise like the fuel pump priming or similar to it. Same noise as when you open a door after the car has been sitting for a while.
My best guess is the diversity antenna is bad but will this cause all the issues I’m having including no more alarm and manual key no longer locking or unlocking all the doors? 2nd guess is the 2.97 volts from the new battery is not enough? Does it need at least 3 volts?(this wouldn’t explain no more locking all doors or alarm with manual key?
I am over an hour from nearest dealer and not looking forward to taking it to them for full diagnostic. Hoping someone hear has some insight as to what could be going on.
Any info would be much appreciated. Thanks

militarydave

Does you car have "Comfort Access"?

rtreyna

No comfort access

donpb

It would help you immensely to purchase a code reader that reads BMW DTC codes.

rtreyna

Do most indy shops have these or just the dealer. Or am i better off just buying one? Do you recommend a certain one, or just go with a decent value one on Amazon?

donpb

Any indy shop or dealer mechanic has one but buying your own is more convenient and the cost of one diagnostic fee will pay for the reader. Amazon has them for as low as $45.

militarydave

I highly recommend the ANCEL brand off amazon.

Best of luck.

rtreyna

picked up an ANCEL BM500 scanner from Amazon for $100. Coming in the mail tomorrow. I’ll run a scan and report back with findings.

donpb

I had an Ancel BM500, Creator C110+, Foxwell nt510, and now I have an Autophix 7910.

rtreyna

Was the ANCEL any good? Reviews seem pretty good I’m just worried it wont be detailed enough to show my issue. Some people saying its pretty good for electronic diagnostic on bimmers. Fingers crossed.