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Discussion Starter #1
HI all .
I have a 98 4.0 with gas conversion.
With the usual battery drain problem.
Due to the weather as of late I have not been able to work what it is.
The other day I went out and the battery was dead (no charge at all)
so charged it up as usual now my remote won't work and I have to EAC it to get it started.
I am thinking it is either I need to sync the key again or the receiver is toast.
Not sure if this is relevant but just before the flat battery the petrol flap would open by itself when exiting the car.
I have tried the resync routine from the forums but no luck so far.
All help welcomed

it has a series 2 rf reciever ..
 

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There is no such thing as "the usual battery drain problem". Your particular rig has an issue with battery drain. I can have my P38 sit for weeks go out and it'll fire up. Battery drain is not in any way usual for P38s.
 

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Battery drain is common problem for p38 as almost all rigs has 1'st or 2'nd generation of rf receiver. Of course it could be also something not connected to those "design mistake". Anyway only 3'rd gen of rf receiver will give you guarantee to not kill unexpectedly battery as only thise version is able to preliminary verified did received code is for p38 or not and will wake up becm only when code is recognized as a p38 encryption. Of course only when your problem is connected with foregin rf signals on or close to 433Mhz.
 

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My flat battery problems are a distant memory now since I bought the Mk3 rf receiver over a year ago. It wasn't cheap at around £280. Also a good battery is essential.
 

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Battery drain is common problem for p38 as almost all rigs has 1'st or 2'nd generation of rf receiver. Of course it could be also something not connected to those "design mistake". Anyway only 3'rd gen of rf receiver will give you guarantee to not kill unexpectedly battery as only thise version is able to preliminary verified did received code is for p38 or not and will wake up becm only when code is recognized as a p38 encryption. Of course only when your problem is connected with foregin rf signals on or close to 433Mhz.
Battery drain is not "Common problem" and there was no "Design Mistake".
As I understand it, The issue arose when, in 1994, the band chosen and assigned to this application was virtually unused. Shortly thereafter, wireless thermostats, and a host of other devices proliferated and were allowed to use the same band, and frequency. (This could not have been anticipated by the designers in 1994) This caused the random issues with Becm's being activated erroneously.
With the problem identified, a technical solution in the form of the Mk3 receiver was implemented. Expensive? Yes, but effective.
 

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Dear Bolt,
I put "design mistake" in apostrophe a specially because I know about ground mentioned by You. Full agree with You here.
Newertheless common problems of MK1 and MK2 of RF receivers are fact, YWY500170 is rare on our trucks and was installed only when final user (during guarantee period) complained flatteness of battery issue. And as I know, ywy500170 was available after end of production of p38. As You mentioned, since years a lot of electronical equipment was used/introduced and is poluting area by it's rf signals nowadays so it is quite obvious that even if first p38 user hasn't any noticable issue with battery the todays user can be facing another situation now. Those situation I observed many times on polish market. Btw - I bought 3'rd generation of RF receiver on internet auction on really low price (10Euro) based only on part picture - when you will see "CE" mark on white sticker, it is huge probability that you see mk3 unit!
 

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Getting back to the original question rather than debating the pros and cons of the different receivers and the reasons for battery draining, a failure to be able to sync the fob is a different matter. Check that the fob is transmitting and the receiver is receiving. You'll need to wait until nightime but sit in the car and switch everything off. Look at the red LED next to the gear lever and it will be glowing slightly. After two minutes it will go out showing that the BeCM has gone to sleep. Press a button on the fob and it should come back on again dimly showing that the BeCM has been woken up. That shows that the fob is transmitting and the receiver is getting the signal but the rolling codes are out of sync. If the EKA code works, then the CDL and keyswitch microswitches in the drivers door latch are OK so you should be able to sync the fob with the key in the door lock method. If pressing a fob button doesn't wake up the BeCM then the fob may be lighting up but isn't transmitting or the receiver has died and isn't receiving the signal.
 

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YWY500170 to fix the battery drain issues wasn't brought out until around 2005 - 4 years after P38 production finished - to finally fix the problem.

As mentioned, the 1st gen receivers have very little filtering and will wake the BECM up with nearly anything.
2nd gen receivers had better filtering in them to filter our erroneous signals on other frequencies - but anything on the 433mhz band will still trigger it to wake the BECM and check if it's a P38 code.
3rd gen receivers do some form of parsing to make sure the code is from a P38 key, and only if it is will it wake the BECM for checking that it's valid for that vehicle.

I'm currently in the process of trying to make my own version of receiver to do what the 3rd gen unit does. It's one of the many projects which have been on the back burner for awhile - as I bought a 3rd gen receiver years ago when mine had battery drain issues.

To the OP... As Richard says - first thing is to see if the key is waking the BECM up - if it is, then SOMETHING is being received, and then it's a case of working out why the key won't sync. If the vehicle is in the same spot as it was when the battery went flat, then sometimes moving it can be all that's needed - if there's enough RF swamping it that is keeping the BECM awake, then it possible it isn't actually getting a decent transmission from the key, and moving the vehicle a bit will be just enough to stop the interference from preventing you from syncing the key.

If you sit in the vehicle, and watch the red light by the shifter (again as Richard mentions) - once it goes out (assuming it does!) give it a minute or 2 before pressing the button on the fob. If the light stays out, then press the fob button. If it comes back on by itself, then something is waking the BECM up externally. You can try disconnecting the aerial from the RF receiver, or the whole receiver itself and re-testing to see if it makes a difference to the BECM sleeping/being woken up, and might help pinpoint whether RF interference is the cause of the problem, or something else is causing it.
 

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ganc wrote:

I bought 3'rd generation of RF receiver on internet auction on really low price (10Euro) based only on part picture - when you will see "CE" mark on white sticker, it is huge probability that you see mk3 unit!
The latest Mk3 receiver should have a green circular sticker on it.

Be careful when buying rf receivers on Ebay. Some unscrupulous sellers put a green sticker on a Mk1 or Mk2 receiver to make it look like a Mk3.
 

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Discussion Starter #10
Thanks for the replies guys .
so far I have only been able to test if the BECM will go to sleep and no it stays on for at least 3 hours will try superlocking tonight to see if that will get it to sleep.
Though the battery has kept charge so far ,so it seems that it is the receiver is faulty??
 

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Not necessarily a 'faulty' receiver per se - as it's is kinda doing what it was designed for at the time - but now there's more wireless about than ever, they do get interference at times.

The next thing to try in unplugging the RF receiver and seeing if the BECM goes to sleep. If it does.. then yes, RF interference is your problem. If it doesn't, then there's something else causing it, and we can look into other troubleshooting options.
 
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