E61 Remote issues

[hodgess]

I have an '08 E61 535ix wagon that I only use a few times a week at most. I am a long-time, very experienced BMW guy with 5 of them in the garage/driveway at the moment, so this is not a basic issue. This is the only BMW I own that does not have comfort access (except for my '75 2002).

The remotes, both of them, fail to work on a regular basis. This most often occurs after the car has been sitting for a couple of days. Normally, I would just assume that I haven't been driving the car enough and that the batteries, which recharge while inserted in the key slot, have not had an opportunity to charge. However, the issue occurs even when I've been driving the car for 30 minutes or more. Also, and this is the real head scratcher, once I unlock the car with the physical key, the remotes will work for a while and then fail again. My Ista-D software does not indicate that there are any issues with the remote sensors or fob charger in the car.

Three questions:
1. How long does it take for a key fob to be fully charged when inserted in the key slot?
2. Is there a technique for replacing these rechargeable batteries? (Unlike the comfort access fobs, these do not have an access panel and there is no "splitter slot" that allows you to lever it open.)
3. Is there a technique I can use to charge the fobs while not using the car?

I have a brand new key fob and the means to program it, but I want to confirm that this is a non-replacable dead/tired fob battery before I do that.


I appreciate your thoughts on this!

[pbonsalb]

Our remotes are weak — they need to be close to the car. There is a battery inside that is not supposed to be user replaceable but a few have done it and there is a company or 2 that does it for a fee. I bought a new remote and it made littleto no difference. Iamcurioys about this as well for my 08 535xit. I have read the antenna in the shark fin could have corrosion. My 08 M3 remotes still work great.

[DaHose]

Look on youtube for "replace e46 key battery". You will find several videos showing how, and some suggestions for charging the battery outside the car.

I replaced my battery. The hardest part is finding the correct replacement battery itself. Just order online and save time calling around locally.

Jose

[pbonsalb]

I bought a brand new remote which presumably had a brand new battery. Made little to no difference in my case.

[DaHose]

I should have included that I replaced the battery in one of mine, and also did not see a significant improvement in performance.

Jose

[pbonsalb]

The antenna will be my next focus.

[Reefin Dude]

if you have the comfort access keys, then the battery is easily replaceable. there is a battery door on the back and it takes a CR2032 battery. you need to take the key part out of the fob, and then pry off the back panel.

wagons are also known to have bad antennae modules located under the rear "wing". the wiring in the hatch hinge can also go bad causing bad reception issues also.

G~

[SteveNYC]

I have an '08 E61 535ix wagon that I only use a few times a week at most. I am a long-time, very experienced BMW guy with 5 of them in the garage/driveway at the moment, so this is not a basic issue. This is the only BMW I own that does not have comfort access (except for my '75 2002).

The remotes, both of them, fail to work on a regular basis. This most often occurs after the car has been sitting for a couple of days. Normally, I would just assume that I haven't been driving the car enough and that the batteries, which recharge while inserted in the key slot, have not had an opportunity to charge. However, the issue occurs even when I've been driving the car for 30 minutes or more. Also, and this is the real head scratcher, once I unlock the car with the physical key, the remotes will work for a while and then fail again. My Ista-D software does not indicate that there are any issues with the remote sensors or fob charger in the car.

Three questions:
1. How long does it take for a key fob to be fully charged when inserted in the key slot?
2. Is there a technique for replacing these rechargeable batteries? (Unlike the comfort access fobs, these do not have an access panel and there is no "splitter slot" that allows you to lever it open.)
3. Is there a technique I can use to charge the fobs while not using the car?

I have a brand new key fob and the means to program it, but I want to confirm that this is a non-replacable dead/tired fob battery before I do that.


I appreciate your thoughts on this!

You can charge the non-comfort-access, non-replaceable-battery keys using an electric toothbrush charger. Found the tip online and it worked for me. We had one key that we'd not used in 9 years and charged it up that way.
BMW keyfob charger - YouTube

Perhaps related? We had a mysterious remote unlocking issue with our 2008 E61. Keys stopped working and we eventually had to replace the diversity antenna (about $350 from Pelican). Bit surprised as there was no obvious corrosion (it had the 'foam pads' service mod applied at some point in it's life and was in good shape internally with no sign of water damage). After running out of other ideas I went ahead and changed it. It's an easy DIY job, ~30 mins after you've taken it off to look at it a couple of times.. Maybe 45 mins if you do it slowly the first time. Remember to put a cloth on the roof to avoid scratches.

Good luck with it.

[hodgess]

Thought I would close this one out. As some suggested, this was just the next failure of the wireing within the rear hatch hinges. I purchased the repair kit and plan on rewiring everyting that goes through that hinge. IN the meantime, I have to unlock the car with a key. You know, the way we used to do it before we got so lazy.

Thanks,

Scott

[Barnesautos]

I used to have an 39 before I got the e61 .
Now my battery failed in the diamond key and it caused me no end of headache as the alarm was set and the key wouldn’t open the car to disable the alarm , so the key had to be used and the alarm wouldn’t shut up . I also read about replacing the battery in the fob on YouTube and the charging of it with the toothbrush charger .
What I’m about to tell you worked for me .

I sat down and thought about when the key gets a charge , well as I did short journeys to work the battery obviously depleted over time , so I thought well the car needs a seriously long drive then to put charge back into it .
Errr no thanks , use to much fuel for starters.
Brain 🧠 wave , I hooked up a decent battery charger that kicks our 20/30 amps to the vehicle and “wait for it” left the ignition on for 5-6 hours . After that time I carried out the re-synchronisation of the key and hey presto I’m back up and running .
I did this every 2-3 months and all was good . I mean driving down the road with the alarm going off isn’t a nice feeling as other people think you’ve stolen it or something and on top of that the indicators don’t work either causing chaos to other road users lol.

I’d be giving that a go as you don’t need to payout for any parts as such , just need to find a garage to charge your car battery with the ignition on or even at home if you have one .

So naturally now as I own a e61 , i definitely set about coding my car so that when the door is open and unlocked with my key blade , the second the door is opened and the alarm starts bellowing I can insert the key into the ignition slot and turn on the ignition and the alarm with stop instantly .
Such a great feature I found on inpa and I did it myself .

[iregj]

So naturally now as I own a e61 , i definitely set about coding my car so that when the door is open and unlocked with my key blade , the second the door is opened and the alarm starts bellowing I can insert the key into the ignition slot and turn on the ignition and the alarm with stop instantly .
Such a great feature I found on inpa and I did it myself .

This is standard on the E61.. What did you need to code?

[Barnesautos]

This is standard on the E61.. What did you need to code?

The alarm disable with key , mine was set to not active .

[iregj]

Weird. When I open with the physical key I just insert the fob to turn off the alarm. Didn't need coding.

[adonnan]

Despite replacing the CR2032 key, I have to have the key out of my pocket before keyless ignition will work reliably. Since I have a wagon, guess the antenna and/or wiring in the trunk is the next culprit? I guess keyless start/entry didn't work great in 2010.

[DRVN2WN]

Despite replacing the CR2032 key, I have to have the key out of my pocket before keyless ignition will work reliably. Since I have a wagon, guess the antenna and/or wiring in the trunk is the next culprit? I guess keyless start/entry didn't work great in 2010.

Yup, you've likely got wiring issues in the hinge area.

[iregj]

Despite replacing the CR2032 key, I have to have the key out of my pocket before keyless ignition will work reliably. Since I have a wagon, guess the antenna and/or wiring in the trunk is the next culprit? I guess keyless start/entry didn't work great in 2010.

The Comfort Access control unit is near the glove box and the interior antennas are below the dvd drive, near the rear air vents, behind the rear seat and in the luggage compartment near the edge. The antenna wires don't run inside the hinges. Try holding your key near those places, maybe you just have a bad front antenna or bad control unit.