E53 Electrical Gremlins

[80stech]

The first post says "keys" but I am assuming you only have one? Do none of the buttons work? The pairing can be tricky because the procedure isn't totally clear on keeping the button pressed. Having a second working key is KEY when one stops working!

[andrewwynn]

You can test the key is transmitting at some stores where they sell key fob batteries. They might have a radio receiver that lights up when it detects a remote signal.

If you have the key open you can also test by watching the battery voltage when you press the buttons. Voltage out the switch doesn't mean the power is going where it needs to go.

When mine didn't transmit the vBat would not drop and when i fixed the solder joints (reflow), then i saw something like 0.2v drop when pressing any button.

I made a thread showing where you can use needles to poke through the key to measure voltage without disassembly. But obviously much easier if you have the key open.


–awr–

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[Juut]

Hey all sorry have been keeping up but was busy


So no joys with the reflows - I had already done this before but JUST incase did it again. I've ordered some new buttons on the off chance one is knackered internally.


But yea single key, I have a spare but its the hard key not the remote locking. I've tried to resync it god knows how many times and it is flat out not working at all so we'll see if the new switchs work otherwise yea I might whip into a local and see if they have a tester, I think timpsons usually have one floating around!

[andrewwynn]

As long as you have the non remote key it’s safe to work on the key.

If you monitor the vBat while pressing the buttons you should see the voltage drop a significant amount the whole time the button is pressed that's exactly how i confirmed my key wasn't working.

You can measure Ω across the switch or voltage across the switch to see if the switch has failed.

In my case switch worked something downstream wasn't getting power.

Even when i reflowed the fault eventually returned and a replacement key was the true solution and even though expensive was worth every penny.


–awr–

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[Juut]

Morning,


Sorry I hadnt gotten back to you a lot happened!


So initially I swapped the buttons for new ones (I do SMD soldering work as a side job) no joys. So good chance I just order a new key.


Anyway the reason it all got a bit derailed is I got a Trans Prog Fail Safe pop up.


Luckily I had just landed at my unit - Code 52/53 (2nd & 3rd Gear Monitoring) No other codes....


I've got the plug to check but otherwise chances are it's the solenoid for 2nd&3rd thats gone possibly MOT tester kindly let me yoink his shiny new snap on along with a slew of historical and now deleted codes these remain. Not terrible but we'll see if the plugs choked up first.


And then to top it off... I pulled my E36 out of mothball to cover while the X is incapacitated only for the fuel pump to fail just before emissions


What a week...

[workingonit]

Originally Posted by Juut

...order a new key ....

the fuel pump to fail just before emissions ....

Been there, done that.

My X's fuel pump failed as I was getting the emissions inspection, though it was running perfectly until then, and I had to get a new "reliable" Valet key the next week, after the pump was installed....

The X isn't running correctly ever since, but hopefully I can make it do so, soon.

So it seems that other X's sometimes have multiple failures on similar timescales, and it's not just the bad luck I thought it was.



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[andrewwynn]

Yours failed *at* emissions!


–awr–

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[Juut]

Sorry, I don't understand what you're getting at?

[andrewwynn]

He went to get emissions tested, and while in the bay his fuel pump died. So he said been there done that to your comment fuel pump died just before emissions.


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[Juut]

Originally Posted by workingonit

Been there, done that.

My X's fuel pump failed as I was getting the emissions inspection, though it was running perfectly until then, and I had to get a new "reliable" Valet key the next week, after the pump was installed....

The X isn't running correctly ever since, but hopefully I can make it do so, soon.

So it seems that other X's sometimes have multiple failures on similar timescales, and it's not just the bad luck I thought it was.



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Oh no the fuel pump failing was on the E36 (as mentioned in the post)


Although the X5 has it's own issue with fuel... ie the connector hose between the two so it's running off the smaller tank currenlty so no dropping below about a 1/4 tank! Pump works fine just that stupid hose between the main/res tanks is busted I just have yet to fix that one