reefguy

hey guys...

I have a question regarding the keyless entry, regarding only the fingerprint entry and also trunk lid lock button not working .. of course the dealership wanted $800. for the fob and the car towed there and an additional $200 for programming if necessary..

The story... so recently i decided to change my wife's 2010 e550 key fob shell, in the process of opening up the fob my xacto blade was accidently stabbed abit too deep, resulting in damaging the pcb board and also a ceramic capacitor, it would be very difficult to fix a
what i see is a 3 layer pcb board. so, i was finally able to track down a exact donor key fob, i swapped out the bga chip into the donor and another chip, eveything works except the keyless entry/fingerprint entry/exit and also the lock button in the trunk lid thats seems to not work, thats next to the
trunk close button on the right side of it.

note: All 3 buttons are sending out the correct 315 frequency signal when they are independently depressed.(according to the frequency checker)

So im trying to figure out what the problem could be, why the fingerprint entry is not working? any ideas as to any other chip that should be transplanted as well? before the chip transplant, everything was working exactly the way it supppose to be. I was wondering if the keyless entry is not working, shouldn't the keyless go would not be able to start the start car as well?

any advice would be greatly appreciated.. thanks

CaliBenzDriver

shucks.... can you show us both sides pictures of the PCB? You got me wondering what else is used to encode the unique ID.

The way doors and trunk are not responsive suggest your keyless module remains unsatisfied.

Is your Ignition switch satisfied with your homemade hybrid key or displaying messages related to unrecognized key...

​​​​​

reefguy

reefguy

the keyless go starting works fine, meaning i can push the start button on car with fob in my pocket.. all the buttons work as they should.

When I damaged it while opening the shell, I may have possibly knocked off a ceramic cap. But the weird thing is my donor board didn't have one either.

CaliBenzDriver

misc chips
I guess these couple left over chips may have something to do with your doors and trunk not playing along.

It's like the key hosts two separate authentications

reefguy

so your saying every chip needed to be transplanted as well? it was my understanding only the bga chip that holds all the programming only? because that #2 chip was damaged/chipped by me..

CaliBenzDriver

yep, I see now... your #2 chip got a generous crack spread across its packaging.


Without schematic, I don't know what these smaller chips are but I can guess: RF amplifiers to pump data bursts through the antenna... so they may host a unique MAC ID the Keyless needs to get paired with.


You can assume you have a working key that needs a fresh registration.
I am not locksmith.

++++ Plan B: "nothing to loose"
Try to move over #1 and perhaps #3 if it's not just a transformer/choke.

You never know, you might get lucky for all your efforts.

reefguy

yup, i could not find the schematics for it either.

I totally agree with you. I guess at this point, i have nothing to lose. if it were my car, id live with it. The frustrating part is my rework station took a dump.

since its the wife's car and it seems that keyless entry is a big deal for her and since i brought this on to myself, i guess the quest still marches on...

thanks.

pierrejoliat

I feel your pain, my wife also refuses to take the key fob from her purse, so always opens with the door handles and starts with the button. I push the unlock on the remote always, go figure... Good luck.
This maybe a stupid question, but did the donor key fob have remote entry? I think so if the keyless go worked?

reefguy

Haha! same here..

but, then again its her car and its a big deal to her. That car has gotten only about 5k miles put on the last 3 years now... I guess she should expects to have it prepped and ready for use, on a mission to go shopping. You know like the Airforce 1.. for the president kinda of thing.

I did get the donor as a keyless function fob, but i couldn't elaborate on what exact features the prior car had and what was programmed to that fob. I just had to verify all the info. numbers under the battery cover was exactly the same as mine. And double verify the pcb
board was the same after opening up the donor fob.( of course you can also tell by comparing the two ).

KEY08

Shop around with area dealers and just order a new key if you only have the one. I know they are pricey but not $800. Going Frankenstein on a donor key fob is a new one on me.

reefguy

well, thats the prices they gave me at my local dealerships and the need to have the car towed there as well.

And, since i know how to component level microsolder, i'd figured at this point what do i have to lose? so far, everything works perfect except the keyless/fingerprint entry only.

'' Going Frankenstein '? i don't think you understand, its just swapping out the brain/programmed chip to another key fob. its no different than getting your laptop fixed because the screen when black.

Left Coast Geek

I read somewhere these keys use two different RF signals, one is used to determine where exactly the key is in relation to the car, so the door handle touch-to-unlock only works if the key is just outside that door and not if its inside, the other is the security two-way handshake.

re swapping chips, its very possible there's different revisions of the circuit design, and parts may not be interchangeable between those revisions. there might even be different vendors, who could use different chips to achieve the same functionality.

cetialpha5

That doesn't make sense if the car runs, you can just drive it there. The programming is probably coming from the service advisers so they can get their cut. It doesn't normally need programming, you just need to go to parts and just order the key. Although the key is in the $500 range. Different dealers charge different prices and sometimes those 10% off coupon codes at various dealers work on the parts. You just need to call around to different dealers. They want to see the car to make sure you're the owner before ordering the key. They will usually price match too so if some dealer far away is cheaper, check with your local one and see if they will price match the other dealer. Programming could involve removing the old key from the system if the key was lost. But that's not your case and they basically just stick the key in the ignition and turn it to see that the key is recognized. You don't really need to pay them $200 for that.

reefguy

You may be correct..

KEY08

When I bought a used 2010 E550, the dealer owed me an extra key as they only had one. When the new key came I picked it up and inserted it into the slot and turned it. The dash showed “key initiating” for a few seconds and then it was good to go. There was no dealer programming involved whatsoever.

pierrejoliat

I would immediately be required to surrender my working key! Does your other remote still work? if so then we know the sensors are functioning and it is in fact the remote? I applaud your ambition and tenacity in changing out components, way over my capability, I have had to purchase new keys twice, but on an '03 and '93 so much older tech, but both just worked when they arrived, since I was a long time customer, I did not have to bring a title and registration to the dealer to place the orders. A quick read of trouble codes may be in order.

LCG may have a valid point.

reefguy

is your e550, with keyless go and keyless start?

CaliBenzDriver

It's kind o' strange to buy a key and drive off without any programming...
I thought dealers needed a locksmith licence to work on any security related parts.

I wonder what WIS says about new keys uptake on these cars

cetialpha5

That's the whole point. You order the key and they ship it out from Texas last time I heard, they just make a new key based on the vin. The dealer doesn't actually do anything. I believe they can go in and remove the old key in case you lost it so someone else doesn't steal your car. But if you have a bad key fob, you don't need that or if you lost the key at home, you don't want it removed from the system in case you find it later. So charging the programming is just a way for the SA to get paid as they also work on commission. You should just go to parts and order the key there. Discount codes and coupons don't work on keys because they consider it parts.

KEY08

Yep, my key for that car came out of the Texas facility and it was good to go after initializing on its own.
I don’t own that car anymore, but it was also keyless go.

Left Coast Geek

on my early/mid 2000s Ford trucks, the car learns the keyfobs. if you want to program it for a new keyfob, you have to re initialize it with all your fobs, so anyone you no longer have will no longer work. no tooling or computer is required, just some silly sequence with the ignition key and various dashboard buttons... lets see...close all doors, open drivers door, press unlock button in drivers door. insert ignition key, switch off->run->off 8 total times within 10 seconds, leaving it in RUN. the doors should LOCK, UNLOCK to acknolege you are in programming mode. for each fob, press a button on the fob, the door should cycle lOCK/UNLOCK, repeat for next fob til done. then turn hte key off, the locks should cycle one last time.

whadda song-n-dance, eh? I remember something similar on our Toyotas of the same general vintage.

KEY08

The GT350 I had, obviously a Ford, allows you to program your own new keys right in the center console as long as you have the two original keys. You can have up to six keys I believe. That’s the way it should be with every manufacturer. I don’t enjoy getting ripped off for such a simple request to have an additional key.

reefguy

thats exactly what i do on my chevy truck to program the key fob..(only 5 times instead of 8, but close enough.)

reefguy

Isn't that the truth!!