Upgrading from Mk1 to Mk3 RF receiver...

awkwardbob said:

Hi, no she’s a Nov ‘97 U.K. model although that would imply the Mk 3 receiver was fitted at a later date.
I did have a replacement key made recently from the chaps in North Wales after my battery ate itself but I’m assuming it was the standard U.K. freq.

I’m more than happy to refund, but I’ll check the unit when it comes back to see if it works on my car (I did test it before selling and it worked fine, plug-and-play as you say) -purely for my own sanity.

Just one question, you don’t need to do that ‘clear RF memory’ in nanocom do you ? -I had been doing that a lot prior to testing as the dead (faulty) battery had put my BECM into that ‘ panic’ condition

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P38 Monkey said:

Just checking my existing Mk1 RF unit, the FCC ID is LQN-5077 which is a 315 MHz licence - see attached.
So my P38 (Japanese import) looks like it has 315 MHz fobs/receiver.
Presumably the UK version (and hence the Mk3 RF unit) uses a different frequency.
(Bob's Mk3 unit does not have anything on the label).
So does that explain the problem??? If so, that is an inspirational response from Marshall8hp above....!
Getting there...

View attachment 256155

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awkwardbob said:

Bingo !
That would presumably explain it, I’ll sort out a refund as clearly it’s of no use to you.
-just glad I didn’t sell you a dud !

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Datatek said:

So Japan uses the same frequency as the USA, we live and learn. The UK and EU use 433Mhz the USA is 315Mhz.
Is the MK3 receiver still for sale when you get it back?

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Datatek said:

So Japan uses the same frequency as the USA, we live and learn. The UK and EU use 433Mhz the USA is 315Mhz.
Is the MK3 receiver still for sale when you get it back?

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P38 Monkey said:

Let me know as I have not posted it yet and could send to another address if required...

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Datatek said:

PM me with the price please.

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awkwardbob said:

Yes it will be, if anyone wants / needs one -or, as Mike says, one could buy it from him

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P38 Monkey said:

Bob, can you message Datatek directly on this ref price? Standing by to post it. Thanks...

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P38 Monkey said:

P38 4.0SE 1997.
Given the battery-flattening tendencies of the Mk1 RF key fob receiver, passing loads of bogus instructions that disturb the slumbering BeCM, I decided to upgrade to a Mk3 version. I have just received a genuine one, but can't get it to work. The old Mk1 is fine and when I swap turn and turn about, the Mk1 works and the Mk3 doesn't. The seller tried it on his P38 with the intention of upgrading, but then found that the one he already had in the P38 was actually a Mk3 (something else was causing the battery drain), hence sold it. The Mk3 worked in his P38 but won't in mine. Nothing about initialising in the workshop manual, which confirms that the RF receiver is not vehicle-specific
Is there some magic initiation procedure?

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Grrrrrr said:

No. Plug and play.

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brianp38dse said:

You may well be up the same creek with one of Martyuk`s filters, if so you can go the cheap and easy route and fit an extra remote fob that will stop all signals getting to the becm unless triggered and you can get the remotes in 433mhz so will be different to your existing one cost about £10
https://www.landyzone.co.uk/land-rover/rf-reciever-work-round.258096/

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Datatek said:

I think Marty's filter is down stream from the receiver in the line to the BECM so will not be affected by the receiver operating frequency.

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P38 Monkey said:

The Marty-filter is between the RF receiver and the BeCM. So it monitors what the RF unit is sending to the BeCM. Assuming the BeCM expects the same baseband bit-stream from USA RF receivers as it gets from UK ones, it should still work. I had better message MartyUK to double-check though....
Running a test right now and the battery is not going flat - obviously my P38 is lulling me into a false sense of security.

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Datatek said:

The BECM seems to be the same for NAS cars as European ones so the bit stream from the FOB's will be the same, only the carrier radio frequency is different.
The MK3 receiver contains a microprocessor configured as a signal processor after the receiver stage to pass only valid signals to the BECM. I'm sure Marty's filter is basically the same.
The MK1 receiver is a terrible piece of design, it will pass any 433Mhz signal to the BECM from any 433Mhz channel. I have not seen a MK2 receiver so I do not know how precise the channel frequency is but it must be better than the MK1.

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P38 Monkey said:

Having seen all 3 "in the flesh", the Mk2 has a metal can over the PCB so presumably stops any spurious RF from entering the system directly onto the circuitry, but of course does not stop anything coming in off the antenna. I believe the main problem with the UK version (433 MHz) is that it is bang adjacent to the civil Tetra (low frequency) cellular network so any Tetra broadcast amp that is not strictly linear will send signals that the RF unit can receive. Can't find anything close to my 315 MHz fob system apart from some obsolete satellite-to-ground kit. Having said that, I am confident that the MartyUK should still work as it is RF-agnostic, but I'll ask him before buying one anyway.
p/s/ Three ways to design anything: the right way, the wrong way, and the way Land Rover do it.

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