Keyless Entry Diagnostics?

[BlackOnBlack]

I got some great info from the forum on the keyless entry/security system. Thanks to everyone.
When I bought the car, I didn't get the remote unit from the mechanic I bought if from. He mentioned that the guy he got it from (original owner) didn't have the remote and the security/keyless system doesn't work.

QUESTION:
Are there any diagnotics I can do on the system without first buying a romote for it? I don't want to spend the money if it's not going to work anyway.

Also, the unit under the rear seat says "BMW Pre-Wired" instead of "Keyless Entry"...don't know if that makes any difference.

Steve

[silverc4s]

Steve:
i do not know the answer to your question, but I am interested, as my 94 540i has become intermittently functional after 8 or 9 years of reliable service. I have 2 remotes & they both act up, so I think it's the in car unit.
Any experts on this system out there???

Also, the unit under the rear seat says "BMW Pre-Wired" instead of "Keyless Entry"...don't know if that makes any difference.

[caqueenslace]

I got some great info from the forum on the keyless entry/security system. Thanks to everyone.
When I bought the car, I didn't get the remote unit from the mechanic I bought if from. He mentioned that the guy he got it from (original owner) didn't have the remote and the security/keyless system doesn't work.

QUESTION:
Are there any diagnotics I can do on the system without first buying a romote for it? I don't want to spend the money if it's not going to work anyway.

Also, the unit under the rear seat says "BMW Pre-Wired" instead of "Keyless Entry"...don't know if that makes any difference.

Steve

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Steve

I have this until in my 95 E34. Can you tell me what that input slot is for?? I see the antenna. Put our input was plugged in but we found the wire frayed or chewed.

What is this and what does it affect?

[caqueenslace]

Steve,

Forgot to mention ours says BMW Remote Keyless Entry on it not PREWIRED.

Denise

[Kalevera]

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Steve

I have this until in my 95 E34. Can you tell me what that input slot is for?? I see the antenna. Put our input was plugged in but we found the wire frayed or chewed.

What is this and what does it affect?

Aha! you were talking about that input, not the ant one. That part is for the microphone -- should sit in the dash/driver's console and reports noises from the cabin (ie - breaking glass) to the module.

Regarding the topic at hand, there's no way to test the system (without a good diagnostic computer) without the remote that I know of. I think it's pretty ridiculous that the mechanic insinuated that it didn't work because he didn't have the fob for it.

best, whit

[caqueenslace]

Is the system required to have the microphone? So if it was chewed off them we should be able to find the other end. I don't think there is a microphone in there..maybe the other owner ripped it out??

Where can I find the microphone in the dash? Can I see it?

Can I ask what "fob" means?

And, did you see our threads, you helped us a lot on what we think is wrong with it. Trunk actuator is bad, it's working fine so far since we disconnector that. And, now the central locking system is working again in the doors but not the trunk obviously.

You were right...no water damage!!! WHEW!!!!. Everything is bone dry!

So just let me know if we need to locate that microphone and fix the plug then reinstall.

THANKS Whit!!!!

[caqueenslace]

I found a lot on these units in the archives.

Good luck...I'm no expert, just trying to heal my sick Bimmer...and we did!

[Kalevera]

I'd disconnect the alarm box completely for the time being. I don't think the mic input is necessary, but having a frayed wire couldn't be helping anything.

Check the wiring harness that runs along the left trunk lid support arm. Wiring commonly cracks and frays, causing all sorts of issues. We talk about it a lot -- a search would render tons of info.

E34 mics went in a blank spot by the fog light switch. It incorporates a LED (system warning light) and the mic. It may also be in the piece of wood trim by the ignition cylinder (more of an E32 thing, but who knows) or in the rear seat part of the center console (under the vent, where the rear heated seat switches would reside) -- most of these systems were installed by the lackeys at dealerships, so....

FOB = generic term for keyless entry remote. Don't know the etymology of the word.

best, whit

[caqueenslace]

Just so you know... the frayed wire is out of the car. It was the plug and only 3" of cord left. So we just unplugged it...The wiring is all like new.

So now it's just finding the wire that leads to the mic. He looked and looked cannot seem to find it. That is why he wants to find the mic and verify one is in the car.

We'll check your info.

THanks again Whit!!!!

[zygoteer]

... intermittently functional after 8 or 9 years of reliable service. I have 2 remotes & they both act up ...

Just a silly thought, but consider that in 94 the best cells around (don't know what type your remotes have though) were Lithium Thionylchloride, with a life (due to self-discharge/leakage) of around 8 to 10 years (other chemical types less than that) ... obviously with some usage its life is going to be less.
Have you checked the cells ?


Nowadays of course, chemistry and purity of manufacture has improved no end, so that 14 years is easily achieved, but unfortunately not yet with the high energy density Lithium Polymers.