The budget E70 has landed.......

[sapphireblack]

...with a bump. Its a 2009 30d in far from pristine nick but equally far from bad nick. I will administer my TLC over time and see what improvements i can make. It has some issues.

I knew the remote was a problem. Since a new battery, (allegedly) the car not the remote, the remote will start the car quite normally but will not lock/unlock the car. I thought the famous battery reset might be the cure, but sadly not. What should i be checking or looking at?

Caveat emptor does apply in as much as i established the car had two keys, but to my disappointment, one is actually a non oem replacement with a blank blade in it. Duped? I suspect i have been but hopefully it's 'easily' resolved. If its an expensive jobbie i think it will be a manual opening/closing car for the future.

[X5Sport]

The central locking is controlled by the Junction Box Electronics module (basically the rear fusebox) actioning instructions from the Car Access System that in turn is getting instructions from the Remote Control Receiver. The receiver is part of the antenna diversity unit and mounted at the top of the upper tailgate.

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You’ll need to get the inner trims off to get to it. It could well just be a broken wire meaning the car isn’t receiving the key signal. You could try holding the key very close to the upper rear window area to see what happens.

What is the condition of the rear window heating and aerial elements on the glass? They need to be intact.

[sapphireblack]

As ever, many thanks. Having poked around on YouTube, almost inevitably, it suggests the battery in the sealed key has died. There are the invetable tutorials for replacing it. Cutting open the key is probably not the hardest task, but one skill I have never mastered is soldering, or is that soddering, according to the YT contributors?

Given that I want a spare key anyway, i may just bite the bullet and commit to a new one, and keep this manual version as the back,up. It would still provide access in an emergency.

I'm hoping thats all thats necessary. I'm reluctant to prod around in delicate ares of the car. I'll update when I have one.

Something else l confess i overlooked was the tool kit, they're all missing bar the tow eye. Ill shop for the red T bar. i think the screwdriver and single spanner i could live without . The car doesnt have locking wheel-bolts,

[Alan Gunn]

Silly question but you did try to resync the fobs to the car ?.

[X5Sport]

…..and a thought from today is are the batteries OK?

You can charge them off the car with one of these: https://www.amazon.co.uk/Certified-Port ... PQ2T&psc=1

Just lay the key on top.

[Leslie]

If it needed a new key battery it would not be the standard key you have to cut open surely , I suppose they fail sometime but are generally long lasting. If you press the locking button on the dash and it locks then at least the hardware can lock which is a decent start.Syncing the fob as said is a good shout , youtube should provide some guidance

That key charging fob is excellent if it works

[sapphireblack]

Budget cars bringing issues is no surprise. Had a moble key guy out today, very, very long six hours here, including a reset of a module from under the drivers side dash*resulted in now having two keys, one shiny new one but neither will unlock the car remotely. £250 poorer to end up where i started, but with a second non working key. Diagnosis / suggestion is the remote aerial sensor, somewhere in the rear roof void, needs replacing. He physically tested every fuse in the boot space to no avail.

*He did access the CAS which he said was corrupted. Part of the reason he was here so long was that was re-programed with help from his HQ

I spoke to the previous owner, who assures me this issue only started when the cars battery was renewed. Having done the 30minutes disconnect with no change, i suspect this X5 may well be a manually, opened and closed vehicle foing forward. I'm not putting hundreds more into it, thats just not the point of owning it.

[sapphireblack]

The dash switch happily activates the locking process. Its now obvious, i think, that the key/s are not communicating with the car?

[X5Sport]

The central locking antennas are in the aerial diversity unit as above. Module A421. It is static sensitive, but a battery change should not have caused any issues. If the radio is working then that tends to show at least part of the module is fine.

The module receives the signals from the keys and if valid passes the ‘OK’ to the CAS. That then in turn sends a signal to the JBE and that triggers the locks. The keys use a rolling code security key. Something pretty odd must have happened to mess up the CAS. When a new battery is installed it has to be coded to the car (you can’t just swap them) and that coding change is stored in the CAS - the same module for the keys. So if the CAS was messed up, did anything else across the systems get affected - like the diversity unit.

If the CAS has the keys programmed in then this points at the diversity module or any of the antennas mounted in the rear spoiler. But if the radio works AM/FM that suggests the module itself. Used ones are about £100, new three times that much.

@Leslie - we use the little puck with the E46 key (diamond key) and it works just fine. An electric toothbrush inductive charger also works but takes a little longer.

[sapphireblack]

I think the likely culprit must be the diversity jobbie. When i asked the seller if the battery had been coded, he said he didnt know. Its on my to do list. Its a Bosch so it wasn't a cheapy compromise. But as you suggest, a battery swap shouldn't mess with any other components.

I'll try the radio in the morning. With the central locking working internally and afaik everything else functioning, I'm perplexed. If it is the diversity aerial i'll.not be throwing £300 at a new one for sure.

This emphatically happened with /after the battery change, i am told.

[X5Sport]

Probably worth having a look at the battery connections and especially a close look at the wiring unit that sits on top of it. I think there is a small wire that comes off the +ve side that provides power to certain systems in the event of an accident - like locking, hazard lights and part of the on board telematics. It’s there because the main +ve cable is sheared to limit current and prevent fires. It’s just possible it’s not connected any more.

The E53 had it, and I’m certain the later cars do too. The X6 has a different battery top, and different diversity system so I can’t compare it.

[Leslie]

Virtually every cac I've ever bought only came with one key till I got the x5 and it would have been a deal breaker if there were not 2 working genuine keys given the cost of them and hassle getting it sorted. I hope you can get this sorted quickly and without too much cost and as I've learned in the past you can't take a sellers word on anything ,if something doesn't work and its gong to bug you then best to avoid but its bought now and if that's the only issue you may have done ok , at 15 years old most of them have many faults .
I turned on my aircon today for the first time in about 2 months and it doesn't work at all now ,was working perfect the last 6 years or so since regas ,not even a little bit and that bugs me , if its just a regas not too bad but if it needs new parts and has lost all the gas I may well have to live with it Oh and sos not available last few days alarm on startup too ,not that its much use now

I spent ages trying to get the central locking to work on one rear door on my cheap passat , it never worked after an accident and door swap to a door with no electric window winder from a door with electric window winder , I changed door wiring , lock, window motor module and guess what its still broke :headbang:but if I plug that wiring to the opposite rear door it works fine I admitted defeat long ago ,its likely a coding issue , ( I even metered wiring to the front door) and id need vagcom to get any further and its not worth the hassle

X5sport thanks

[sapphireblack]

All the radio functions are A1 so no progress. I have a bad feeling about BMW scanning the car. Prophets of doom will possibly see the car or me scrapped!

Good point to check the plethera of wiring attached to the battery. I have fully disconnected it once, but i will check it again for anything loose. Though if the remote only is a problem, i cant see that being the issue emanating from the battery, though that was the coincidence i understand.

[X5Sport]

BMW will probably charge you £200 to gave a look, it won’t help them so they’ll just start changing things on your dime. That’s the bit that really annoys me. If you change it and it doesn’t work then I should not be paying! I had that argument about 17 years ago with the E53 when presented with a £500 bill for something that caused more issues than it fixed. On that occasion I won. Funny how a stand-up row in the showroom can have that effect

If you haven’t got anyone local with their own scanner that could help out, then a Bosch Autocentre may be able to. Much cheaper than a main dealer.

[sapphireblack]

Ill look for a Bosch centre in the near future. I have some travelling to under take soon, time is tight.

The car received a lovely clear mint windsreen today, part of the purchase agreement. Best part of the car right now