habbyguy

I'm a big fan of the two-way (bi-directional) scanners. My assumption (subject to update) is that most of the folks here are at least slightly interested in some level of DIY. They would no doubt benefit from having one of the scanners, as parts and (shudder) shop repairs on these vehicles are SO expensive that a little quality diagnosis info could pay for the scanner in no time.

That's not to say that everyone needs the all-singing, all-dancing uberscanner. But the frugal approach I used for my scanner was to buy the Autophix 7910 (easily had for under $100 from eBay vendors, for example). I (being an anal infomaniac) also had a laptop with INPA / ISTA but found that the Autophix scanner was a whole lot easier to use for 90% (or more) of what I actually did.

Greggo

How was your guy testing the key? "Went back there...," Back to the tailgate, back to his shop, where did he go?

I have a gadget that will tell if the key is transmitting. There is nothing on the car that will tell you if it is receiving a signal. If the CAS received a correct signal, the remote would be working.

If the key(s) are not transmitting a signal, you should buy a new key from dealer. This really is the best option, but not cheap.

Also not certain how the antenna amplifier was checked out as good. You mentioned a shop or dealer looked at this and said it was not the problem. Was it opened and visually inspected, put into another vehicle, etc.. ODB scanner cannot diagnose this component. There is a way to view the radio signals, this is very technical and only helps if the radio is working, to diagnose an antenna signal issue.

Are there any other issues with the tailgate? Window glass does not open, rear wiper does not work, 'door open' error when closed, rear defroster does not work, lights that do not work? Do ALL radio bands work as expected?

Based on what you have said (assuming the amplifier and key are actually good,) the wiring IS the next step. It is such a common issue. My E61 radio worked fine, the remotes would not work. The amplifier was bad, and broken wiring.

Riffolen

Key was tested with some weird device (device that had hole on top of it) and it was not seeing any signal.
Amplifier was indeed tested by dealer, not sure how they did it , since you can't see what they are doing with your car but somehow.they tested it.

"Window glass does not open, rear wiper does not work, 'door open' error when closed, rear defroster does not work, lights that do not work? Do ALL radio bands work as expected?"
Everything works fine , just not the remote key.

Still I wonder if I put new chip inside the fob , can I just teach that key to car or it needs to be programmed ? Making a new key is mad expensive (300 per key) and if it's not solving the issue , I have to pay 600 for wires, so I'm trying to be sure what causing the issue before taking first step , chip change looks like cheapest test but idk

spectre6000

What do you mean by "chip"? The whole PCB? That's essentially the same as getting a new key, only with extra labor. An OEM PCB (which almost certainly isn't an option) will be just as expensive as a whole new key, if not more. An aftermarket PCB will have all the expected challenges on top of that, assuming it exists either. If by "chip" you mean some component ON the PCB which has failed, are you desoldering/soldering components on the factory PCB? I have the soldering station and stereomicroscope required to perform that sort of task in my office, but short of knowing or being someone like that, you're not likely to find anyone willing to tackle such a task. Any microcontrollers will require programming, assuming they're not proprietary and available at all, and you have access to the tools and code required. Even if you make the physical interface, the code for that will be under lock and key available only to BMW and necessary suppliers.

If you're looking for the cheapest way to figure out if it's wires or key fobs, go look at the wires. Cost = $0. If you're afraid to work on your car and/or don't have or have access to the appropriate diagnostic/service software, buy an aftermarket key and have a locksmith program it (that is usually doable with a shop level scan tool). If that doesn't feel good enough, buy a single fob from a dealer.

Riffolen

By chip I mean this https://www.xdalys.lt/ee/product/10479087038/
I'll take amplifier open tomorrow if I get some free time to see how it looks there , maybe the water damage can be seen or something
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spectre6000

Your key must be different from mine. Looks like the older blade style with the diamond shaped fob on top. Ours are rectangular fobs, and the blade is an insert that only works in the doors in emergencies.

The diversity antenna is certainly a piece of the puzzle that warrants a look, but the wiring harness is what's been called into question. It goes through the hinge under a cover and through the headliner. If you look at the photo Greggo posted, you'll see a nice and easy way to access it.

Riffolen

Yeah it's diamond shaped key fob .
I'll attempt to look at wires at hinges but if it's so costly to repair wires then I doubt its easy to access

spectre6000

Accessing it to inspect is not hard. Replacement takes more time, but still isn't hard. I had my headliner out a few times to diagnose and fix a leaking sunroof. Did it solo over the course of a few hours on a nice summer day.