Cheaper solution: Repairing a defective BMW key

BMW provides replacement key fobs for obscene prices, if I understand, upwards of Rs 60k.

BHPian dinu2506 recently shared this with other enthusiasts.

I'm not sure of the latest BMW cars but the 2012 BMW X1 that I have and the 320ds etc of that period in India most probably would have Key Fobs that are fully sealed units. These are called "Non-Comfort Access" fobs. In global markets, there are also cars that come with "Comfort Access" key fobs that have a replaceable CR2032 battery which is the norm in most other cars. I'm still not sure why we were given the "Non-Comfort Access" key fobs. These are fully sealed units with a rechargeable battery called VL2020. These are supposed to last the life of the car, which it probably will if used the way it is supposed to be used and the dealer specifically informs the buyers about this.

But I don't remember my dealer telling me about this when I bought the car and it was only recently I came to know (after one of them failed) that the fob comes with a non-replaceable rechargeable battery. The correct way to use the key fobs is that - either both fobs are used in parallel by two people, or if only one is used at a time, make sure you switch the fobs at least once in 3-4 months to be on the safe side so that they get charged during usage. FYI, the fobs get wirelessly charged when inserted in the slot while using the car. Unfortunately, it was too late by the time I read up and understood about this. One of the fobs was lying unused for more than 18 months and when I tried using it, it was dead and the doors were neither locking nor unlocking. The other fob was working perfectly. Now started the enquiries and was shocked at the options.

BMW provides replacement key fobs for obscene prices, if I understand, upwards of Rs 60k. Checked with my FNG and they too could not help and said we need to get the replacement from BMW but said he could convince the dealer for a goodwill warranty and get it at 50% cost which itself was too much for me. The thing is that the key fob still works when inserted in the slot and the car starts and runs (later on I found that for starting and running the car, the battery is not needed at all). The locking and unlocking would have to be done manually using the pull-out physical key. This was fine for me and made me decide that I'm not spending this kind of money for getting a new one. Tried some jugaads of trying to recharge the fob by placing it on wireless phone chargers overnight and also connected the car battery to a charger and left the car switched on overnight. But nothing worked and the key fob was unable to open and close the doors. So, I concluded, either the battery was totally flat to the extent that it cannot be recharged or there is some problem with the PCB. The gut feeling was that the battery is dead because I have hardly used this fob much.

Meanwhile, I also started googling and came across many videos where people opened up the key fob, de-soldered the VL2020 battery and replaced it with a new one, re-soldered the terminals, and sealed back the case. Was not sure if I should try it as there were also a lot of reports where it did not work even after replacing the battery. Firstly, I checked the availability of the VL2020 battery - this is the same size as a CR2032 battery but has rivetted pins at a 90-degree orientation for the positive and negative terminals. There are also pins at 180-degree orientation but the X1 key fob needs one with 90-degree orientation. Not freely available and none of the popular sites had them but came across a seller STOPSHOPSWIPE who was selling for around Rs 1300.

Before placing the order, I mentally got prepared to open up the fob. The reason was as follows. Firstly, I had a working fob, secondly, I knew the battery is only needed for opening and closing, so worst case if it does not work, I can still use the physical key. Opening up the key fob was much tougher than I thought. It's a really strong seal all around, so you need to use a really good strong blade and be very careful not to insert it too much inside and unknowingly damage the PCB. Never try to pry open with a screwdriver or anything, it will damage the case for good and possibly make it unusable. Once that was done (took a good half-day and a lot of patience to make it in two halves), and de-soldered the VL2020 from the PCB. Checked the voltage and was showing only 1.69V (as against the rated 3V) which was the reason why it was unable to recharge. Before placing an order for a new battery, I still wanted to check whether it is a battery problem and thought of a jugaad. Got a CR2032 that was lying around, soldered short wires to the positive and negative sides and connected these wires to the points I de-soldered on the PCB. Took the PCB along with the jugaad CR2032 and pressed the buttons on the PCB. The X1 happily unlocked and locked. The third button for opening the rear hatch also worked. It was now certain that it is nothing but a battery issue.

Immediately placed an order for the VL2020 battery with the 90-degree pins. Now, this was frustrating. They took a full 6 weeks to deliver this item to me, in spite of repeated follow-ups. Finally, it came and immediately I got on to the job of soldering in the new battery. Took the PCB to the car and it was working. Brought it back, placed it inside the fob case and used Fevibond to seal it back. As I said, there is no way to avoid damage while opening, so it is virtually impossible to have a clean edge when fitting back, but not too bad either. Availed the services of my daughter who has steady hands and is good at painting, to touch up the edges with black enamel paint. Overall, a worthwhile effort, and really happy and satisfied at bringing back the fob to life.

I would assume many BMW owners might be facing this or probably have not even realized one of their fobs is dead. Hopefully, this might help you with a solution rather than spending big money on a new one.

Key points:

• If you have both fobs working, please make sure you keep using both and not leave anyone unused more than 6 months - this is something the dealer should tell the buyers
• Be extra cautious using the blade to open. Invest in a good quality blade and make sure you go just deep enough to cut the seal and not more
• Have a lot of patience while doing the above
• Its a small PCB, so exercise caution while de-soldering and re-soldering so as not to touch or damage nearby circuits
• Be open to accepting some amount of damage to the case edges where the knife is used, it's unavoidable
• Never try prying open with things like a screwdriver as it is sure to break the case - you need to cut open all around with the blade.

The following pictures should give you an idea and hopefully, they help!

Here's what BHPian govigov had to say on the matter:

Very useful DIY and it should be informational for many BMW owners. Even with 2 people driving the car, it is usual for Indian families to keep one key safe while the primary key changes hand. In situations like this, it is bound to happen

Also, another lesson is, make sure you check both the keys when shopping for used BMW's, and don't think that it is an easy affair to change batteries.

Thank you very much.

Here's what BHPian OEMplus55 had to say on the matter:

Fantastic thinking, thanks for sharing with us. Never knew this was a potential issue with key fobs. The eye-watering replacement prices seem squarely aimed at squeezing customers dry just because of the brand value. Love that you refused to be taken for a ride just because their corporate policy decided on ridiculous pricing.

Any idea on what the commission for dealerships looks like on these? Even with the offered 50% discount, their margins could be significant. Might be a reason why dealerships do not really mention this much. At least in my experience with premium dealerships in India or abroad, I have never heard this topic mentioned.

Will definitely let friends and family know to switch up usage between primary and spare keys!

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