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E87 120d key fob doesn't work. Battery replaced. Central lock works via button on dashboard.

12K views 14 replies 9 participants last post by  MaBenza 
#1 ·
Another problem.

Key-fob doesn't lock/unlock the car.
Firstly I received a warning light that key is on low battery. But the key worked perfectly. After some time warning light disappeared and I couldn't lock or unlock the car. So I thought it was a battery, because central locking button on dash works perfectly.
1. Battery was changed;
2. After some research in google I tried to check fuses (2, 19, 56, 57, 53) and they are all in good shape;

Do you have any ideas how to solve this problem?
 
#2 ·
Does the fob allow the car to start? Is the problem JUST with opening/closing, or is it ALSO with starting?

There are several potential issues, and you've dealt with two (battery and fuses).

The fob may have got out of sync with the CAS; if you can get it to work to start the car, then it should resync.

As the lock button on the dash works, there no problem with the mechanism itself; that probably narrows it to the antenna/receiver.
 
#5 ·
Guys, thank's for help.

The fob allows to start a car and the problem exist only with opnening/closing. As I sayed before central locking button on dash works perfectlly.

I don't have a spare fob to try it, but I tryed to change a rear view mirror - ir didn't helped.

Any other ideas how to solve it? It's really anoying to open car with key on winter.

Looking forward to hear some other advises. Thank you!
 
#8 ·
"Aerial amplifier with aerial diversity for FM
The aerial amplifier compensates for losses that occur in the aerial line. The aerial diversity function makes available the signal from the aerial with the best reception to the radio.

E81, E87
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.

The aerial amplifier with aerial diversity for the FM 2 to FM 4 aerials is installed on the inside of the boot lid above the rear window in the area of the auxiliary brake light."

From , just over half way down.

I doubt that'll be your problem, but no harm looking :)

Also, try reading this lot - including links within; some possible diagnostics and solutions for you
 
#9 ·
Nottsknots, thanks for the links. It is very useful information.
I have ordered used aerial amplifier, it should be delivered tomorrow. I think I will be able to change it on weekend, after that i will inform you all :)

Thank you!

Nottsknots said:
"Aerial amplifier with aerial diversity for FM
The aerial amplifier compensates for losses that occur in the aerial line. The aerial diversity function makes available the signal from the aerial with the best reception to the radio.

E81, E87
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.

The aerial amplifier with aerial diversity for the FM 2 to FM 4 aerials is installed on the inside of the boot lid above the rear window in the area of the auxiliary brake light."

From , just over half way down.

I doubt that'll be your problem, but no harm looking :)

Also, try reading this lot - including links within; some possible diagnostics and solutions for you
 
#10 ·
mantego said:
Nottsknots, thanks for the links. It is very useful information.
I have ordered used aerial amplifier, it should be delivered tomorrow. I think I will be able to change it on weekend, after that i will inform you all :)

Thank you!

Nottsknots said:
"Aerial amplifier with aerial diversity for FM
The aerial amplifier compensates for losses that occur in the aerial line. The aerial diversity function makes available the signal from the aerial with the best reception to the radio.

E81, E87
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.

The aerial amplifier with aerial diversity for the FM 2 to FM 4 aerials is installed on the inside of the boot lid above the rear window in the area of the auxiliary brake light."

From , just over half way down.

I doubt that'll be your problem, but no harm looking :)

Also, try reading this lot - including links within; some possible diagnostics and solutions for you
I have the exact same problem with my vehicle at the moment that seemed to have started after recently installing an after market stereo. I have taken the same steps in checking fuses and rrplacing key fob battery, replaced rear view mirror with known to be working E87 one and also just ordered a new (used but working) diversity antenna amplifier as a last resort before I am completely confuddled.

The extra bits of info I have is that I also have a second key and it is the same issue on both. Both keys have also been tested by a garage and are putting out strong 868Hz signals so no issue with the keys. The manual key also unlocks and locks the central locking mechanism normally, so Jo issues there, and the key is recognised by the car and starts etc. I have also done a Carly Pro and a professional garage diagnostic on it and both come up with a "DWA-LED defect" fault, even though I know it is not as it is the same on two mirror units.

Have you done any diagnostic scan on your car?

Oh, and also one thing I have discovered (I think, but not convinced) on my car is that when I put auto wiper on it seems to just wipe every 6 or 7 seconds regardless of how heavy the rain is. This might be me looking for something that's not there, but wondering if this means it a power supply issue in some way from the the headliner dome light to the rear view mirror cluster (which is also where the rain sensor is). You noticed anything like this in your vehicle?
 
#11 ·
mantego said:
Nottsknots, thanks for the links. It is very useful information.
I have ordered used aerial amplifier, it should be delivered tomorrow. I think I will be able to change it on weekend, after that i will inform you all :)

Thank you!

Nottsknots said:
"Aerial amplifier with aerial diversity for FM
The aerial amplifier compensates for losses that occur in the aerial line. The aerial diversity function makes available the signal from the aerial with the best reception to the radio.

E81, E87
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.

The aerial amplifier with aerial diversity for the FM 2 to FM 4 aerials is installed on the inside of the boot lid above the rear window in the area of the auxiliary brake light."

From , just over half way down.

I doubt that'll be your problem, but no harm looking :)

Also, try reading this lot - including links within; some possible diagnostics and solutions for you
Have you done this yet? What was your outcome?
 
#12 ·
So far I have%

- checked fuses and installed LED fuses with none lighting up, i.e. non blown

- had keys checked and tested by a garage and both my keys are working and sending out 868Hz signals

- keys are synced to car

- central locking works perfectly with manual key lock/unlock and via dash button

- immobiliser works fine as once door is opened my alarms go off but placing key in holder stops alarm and unlocks the car for driving etc

- rear view mirror has been changed to a known to be working one

- diversity antenna amplifier has been changed to a known to be working one

So far, bone of these steps has resolved it. I recently visited a BMW dealership and discussed this with them. The engineer there said they would normally go through it logically with 1. keys; 2. fuses; 3. rear view mirror and 4. diversity antenna amplifier and that they would expect to have resolved it by then. If not, they said they would then have to check the wiring and would probably start with the rubber tube hinges on the boot coming from the diversity antenna amplifier and then work back to the mirror and then to the junction boxes from there.

Sounds fun...

.... anybody got any brainwaves or experienced something similar and fixed this kind of issue?
 
#13 ·
Bunford said:
So far I have%

- checked fuses and installed LED fuses with none lighting up, i.e. non blown

- had keys checked and tested by a garage and both my keys are working and sending out 868Hz signals

- keys are synced to car

- central locking works perfectly with manual key lock/unlock and via dash button

- immobiliser works fine as once door is opened my alarms go off but placing key in holder stops alarm and unlocks the car for driving etc

- rear view mirror has been changed to a known to be working one

- diversity antenna amplifier has been changed to a known to be working one

So far, bone of these steps has resolved it. I recently visited a BMW dealership and discussed this with them. The engineer there said they would normally go through it logically with 1. keys; 2. fuses; 3. rear view mirror and 4. diversity antenna amplifier and that they would expect to have resolved it by then. If not, they said they would then have to check the wiring and would probably start with the rubber tube hinges on the boot coming from the diversity antenna amplifier and then work back to the mirror and then to the junction boxes from there.

Sounds fun...

.... anybody got any brainwaves or experienced something similar and fixed this kind of issue?
The problem with the rain sensor happened to me in my old bmw e46, it cleaned at equal intervals of time.

Check fuses and I did not see anything, time later I looked at it again and a fuse was broken, I replaced it and it worked again.

check the rain sensor
you should check wiring if the fuses are good, because in our 1 series the transmitter is connected together with the rain sensor
 
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