Sooz car is flattening its battery every couple of days. I've invested in a Kaiweets HT206D Amp Clamp and nerfed the bonnet switch so everything sleeps with the bonnet up. The pattern after leaving the car double locked over an hour is 0.25-0.35 for 2 mins, then 0.80-090 for 2.5 minutes. My plan is to pull each fuse during the high drain phase to see when it drops, and by how much.

1 Does anyone recognise this pattern?

2 How do I bypass the driver's side door switch to test the ones under the seat if the under-bonnet fuses don't reveal a problem?

Guessing you already know about the alarm/RF problem plus the BeCM staying awake for over 2 minutes etc ? If not search for BeCM SID on here...
As for the 0.8-.9A drain it could be a few things (!!) but I would start with the EAS... so try pulling out its Timer Relay under the LH seat ?!

Probably the easiest way to 'bypass the drivers door switch' is just to use a screwdriver to simulate the striker ?
Needs a calm environment (eg. garage) of course due to motion detector (alarm)

In my previous life before retirement, my work involved tracing this sort of thing. I would say that the BeCM is sleeping so you should have around 0.03A (30mA) but when it is awake it will rise to just under an Amp. For it to cycle it could well be something transmitting every 4-5 minutes so the BeCM sleeps, is then woken up, it waits then goes to sleep again and the cycle starts again. Favourite source at that kind of interval, would be the outdoor unit for a wireless weather station.

But, as Dave has said, the BeCM SID has a list of things that can wake the BeCM up and a flowchart to follow to identify what is the cause. I posted a link to it here https://rangerovers.pub/topic/3311-reconnecting-battery-alarm?page=1#pid40747

+1 on using a screwdriver to close the door latch, while door is open. As long as the BECM thinks the door is shut, then it will let you "lock" the car for sleep tests.

It's also the best way to test latches, because you cannot get locked out, and can still remove the latch to change motors and/or microswitches.

davew wrote:

Guessing you already know about the alarm/RF problem plus the BeCM staying awake for over 2 minutes etc ? If not search for BeCM SID on here...
As for the 0.8-.9A drain it could be a few things (!!) but I would start with the EAS... so try pulling out its Timer Relay under the LH seat ?!

Probably the easiest way to 'bypass the drivers door switch' is just to use a screwdriver to simulate the striker ?
Needs a calm environment (eg. garage) of course due to motion detector (alarm)

I'm aware of the RF issue, we fell foul of CCTV in my car. But my almost identical (1 year younger) Vogue parked next to hers isn't showing the same symptom. I've also seen the joke "solution" with the aluminium box on the circuit board.

I thought the BeCM timeout was longer, so I've been giving it 15 minutes.

We've removed the CD changer and Satnav from the boot area. Satnav head unit TBA.

Thanks for the tip about the black timer relay. Wed pulled the under bonnet one with fuse F29 (but missed fuse F40). I'll put those back and do what you said.

I'll see if can figure out where to stick the screwdriver for the drivers door!

Thanks for the help. This forum is priceless.

PS I'm leaning towards it being something inside the car, as there's a lot of stuff powered while ignition is off, right?

There shouldn't be. Radio has a permanent supply to keep the memorised stations, clock, alarm and that is about it once the BeCM has gone to sleep. That happens 2 minutes after no inputs to trigger it. Easy check you can do is to sit in the car at night. While the BeCM is awake, the red LED next to the gear lever position will be glowing very dimly while it is awake and will go out once it is sleeping. So if you get into the car, close the door, sit there watching the LED and you should see it go out after 2 minutes. If it is the BeCM being awoken by something, you will see it come back on again at the time the current draw would go up again. You can easily wake it at will if you have a keyfob for your other P38 by pressing a button on that. With a Gen 1 or 2 RF receiver, it will see the transmission from the other fob and wake the BeCM in anticipation of receiving a valid code, (which it won't get as the fob is for the wrong car) and that will start the 2 minute timeout again.

The SID gives a list of all the things that will trigger it and wake it up (or prevent it sleeping in the first place) so you can go through the flowchart and isolate which input is triggering it if it is being woken by something.

Okay, removing the EAS delay relay stopped the cycling. Thank you!

Sooz is going over the flowchart to decide what keeps waking it up, as she designs train signalling systems for a living.

I'm looking forward to just following instructions for the rest of the day!

This morning I dropped my P38 off at a new place that I have found that specialises in P38s & seems very knowledgeable. Importantly he was happy for me to supply the parts (stainless steel exhaust & lambda sensor) & he will just charge labour for fitting them. I don't have a pit or lift & am getting too old to be scrabbling about in the dirt under the car so this was ideal. He had three other P38s in the yard plus a few other makes.
He dropped me off at the station for a short rail journey home & took the opportunity to drive my car. The reconditioned engine of course runs beautifully but steering & suspension was all pronounced as up to normal P38 standards. I asked about the stiff gear change. He said that the other identical Vogue that he had in the yard is exactly the same. He is going to check over the car for me while it's on the hoist. He mentioned that for example corrosion on the rear brake pipes is often overlooked even by MOT testers.
I hope that I have found what I am looking for ie a reliable mechanic who knows P38s & can undertake work that is beyond me. I'm picking up the car next Wednesday.

Chasman wrote:

Okay, removing the EAS delay relay stopped the cycling. Thank you!

That's odd, it's only supposed to wake up every 6 hours?

Richard, yes, and that's what I thought too... and that the Timer Relay was only supposed to operate for 20 seconds every 6 hours... under BeCM control...

Ok, (Long story short) I had a strange battery-flattening problem myself and (after I had eliminated the more obvious culprits by observing the BeCM/Led combo) I suspected that the EAS 'self-levelling' routine was happening more frequently than it should, (probably complicated by a slight bag leak ?) so I started investigating further, first via the EAS ECU (connector) and then the Timer Relay and the problem (apparently) disappeared...

Whilst I had the Timer Relay out I opened it up and used a soldering iron on some dry-ish looking joints on the little PCB etc inside...... but I don't know if this was the problem !! ie maybe it was operating for much more than 20 seconds - as the EAS dance frequently happened as It would (too) often be on the bump stops each morning as result of 'something odd' happening..

So, another of those frustrating situations where we "think we have somehow sorted it - but maybe haven't", but of course we all know that the EAS runs on Magic anyway...

That said the problem did not re-occur however...

Chasman: : As an 'experiment' try a standard 4-pin Relay instead of the Timer one; the Self-Levelling won't work then (nor EAS Diagnostics either) but it does stop 'cycling' it really might be a Timer Relay issue like mine was ...(?)

davew wrote:

Richard, yes, and that's what I thought too... and that the Timer Relay was only supposed to operate for 20 seconds every 6 hours... under BeCM control...

No it isn't, the relay contains the timer (probably by a 555 timer chip or similar) and isn't controlled by anything else, it just wakes up. If you look at the diagram, it has permanent power on one side and ground on the other.

Ah yes, I remember that now, it is really quite crude, and thus it was obviously (probably !) not the chip itself but the (soldered) connections to the associated resistor/cap on the tiny PCB that were "iffy" ?? If so thus just resolved with some flux - not some magic.... ?

That said mine does not have permanent power on one side anyway now - as I also did this anyway !
http://p38.stockholmviews.com/eas/eas-timer-shutoff.jpg

PS: Can't find my photos of the suspect joints inside the Timer Relay (yet) but it was 10-12 years ago....

Right. Humble pie time.

Pulling the EAS timer hadn't stopped the cycling, just as you' predicted. We didn't wait long enough. It did reduce the current to 0.55. But running was still 2.0/2.5 mins.

Sooz followed the flow chart, mapped it back to the fuses and found F15 to be the cure:

• Rear Wiper
• RF Receiver
• Tailgate Central Locking
• Left and Right Hand Amps
• Subwoofer
• Load Area Lamps

From your advice I concluded I dismissed the RF in haste. We swapped the cars around. They're literally side by side.

The cycling has stopped. Only at this point I remembered Mr Griffith's the physics teacher saying "All electromagnetic waves are inversely proportional to the square of the distance from the source "

That means the car has around 1/9th to 1/16th less signal in the space furthest from my workshop. Which used to be my home office and has a burglar alarm and WiFi access point...

My car, oddly, is unaffected by being closer. We're pulling out Sooz RF module for comparison.

Thanks again. Humble pie is yummy now we are closing in on a fix.

This is the bad one from Sooz 2001 car.
It's screened.

If pic doesn't work can we work through fixing it. It's worth a thousand words! No text or description changes, tag direct from forum software

Well at least Mr. Griffith would be impressed you remembered the Inverse-Squared Law: Pity he was not able to explain that to LR 30 years ago as their RF Engineers were so bad.....

If it helps the first time I found out about the dubious P38 alarm was on a Petrol Station forecourt - for 3 Hours.(!!)... and it was only resolved when I (finally) realised the car was directly in line with a short dipole antenna on their (RF based) credit card-verification system. Pushed it 10 feet away and all was fine.... Most RF sources are better hidden though...

Your pic is of a 'second generation' RF receiver... they put the whole thing in a can, presumably to (try to) screen it against 'spurious RF ingress' & etc.. they failed, again.

If you disconnect the blue antenna wire from the receiver, you'll need to be closer for the fob to work but it will reduce the interfering signal it it receiving.

I have the same, something my next door neighbour has will keep waking up the Ascot but not mine as the Ascot is a 96 with the early receiver, mine is a 98 but with one of Marty's filters on it. If I park mine nearest the neighbours house with the Ascot the other side of it, not a problem with either, if the Ascot is nearest the neighbours then the BeCM is constantly woken up.

davew wrote:

Well at least Mr. Griffith would be impressed you remembered the Inverse-Squared Law: Pity he was not able to explain that to LR 30 years ago as their RF Engineers were so bad.....

It was BMW at the time and the 7 series of similar vintage was just the same. The receivers were made for them by Siemens but made to a price. When I sent a report as to why they suffered it was passed through various departments before ending up at Siemens who's reply was "When you are only paying 0.09 Euro per receiver, you can't expect quality"

Yes, we can't see your Sooz pic

You can now, I've edited the post.

Interesting info Richard, similarly a decade or so I also traced their (original German manufacturers) EMC (Susceptibility) Certification right back to a company in Ireland: They refused to give me a copy and constantly just referred me back to the LR " who gives a ** " Department too !

Thanks for editing Chasman's post; I have now edited mine

The system operates on nominally 433.98 MHz and the Gen 1 receiver was appalling, it would respond to any signal between about 425 and 440 and wake up the BeCM. I say nominally as external influences will affect the precise operating frequency so the receiver needs to be wideband to a certain degree. Just not as wide as that of the Gen 1..... The Gen 2 had much better selectivity so would only respond to signals much closer to the operating frequency but will still wake the BeCM upon receipt of a signal from any other licence free short range device in that band (433.05 -434.79 MHz). The Gen 3 receiver performance is pretty much the same but the difference is that it doesn't wake the BeCM until it sees a valid P38 code.

Marty's RF filter does the same thing, the receiver, irrespective of which one, receives a signal, instead of passing it directly to the BeCM it is passed to the filter which checks to see if it is a valid P38 code. If it isn't, it rejects it but if it is the code is then passed through to wake up the BeCM. All P38 codes have the same pre-amble before sending the individual code for the car so all will wake up the BeCM but only the correct, matching, code will turn off the alarm and immobiliser and allow the engine to be started.

Good board from my car from previous MY. No Faraday cage. Is the sub-board a filter? (Wrote this before hearing how Marty solved it).

We need both cars working for Monday so we'll leave the faulty car on charge and in the furthest space.

3rd gen boards like this one are £169.49 from East Coast 4x4. There's 200 percent brand tax on the LR version from LR Direct so we've ignored that.

I assume we'll need to use the Nanocom to match the 4 digit codes? Sooz car wouldn't start without it fitted.

https://photos.app.goo.gl/LvJyc7zxu1CVGMWo9

https://photos.app.goo.gl/PJ3DnvM3NfcuPtSn6