P38A New Land Rover owner - Is my car immobilized?

I've been a Range Rover owner for only a week and a LZ member for less than that. My introduction thread is over here, https://www.landyzone.co.uk/land-rover/hello-from-sweden.325032/ . I've posted my thoughts and actions on the car since I got it a week ago, if it might be of any relevance or interest to anyone reading this thread and hoping to give me a hand.

The car in question is a P38A 4.6 HSE -99 (Bosch engine).
After having a drained battery, then jumpstarting it without problems, then having it drained again two days later and again jumpstarting it without problems, it was drained a third time at which point I didn't bother jumpstarting it and just left it charging overnight, the car will not start, but the starter engine runs. The dash display says nothing about immobilization, but after doing some research I'm starting to think it might be the case. I have checked the spark plugs and there's no spark when cranking.

It is my understanding that it is quite common for the becm to become unsynced with the ems, and that there's something called a syncmate you can use to deal with this, but I'd like to hear your opinions whether you think this might be my scenario or if it is something else?

Sounds like you need a syncmate I carry one on board but have never needed it, best get on the bay lots on there to choose from.

On that Model year if it is immobilised by the BeCM it just says engine immobilised and won't even turn the starter over usually.
If it is an absolute emergency try disconnecting the battery. Leave it for a while. Put the key in at position 2 and reconnect the battery. Then try starting it.
Not a preferred approach. But has got mine going when all else has failed me in the past. YMMV and no guarantees given. Just what I have experienced myself.
Good Luck!

Well it's not an absolute emergency because I will be away the entire week working so I won't be able to use it until thursday anyway. I simply want the car in a properly working state. But I will try your suggestion on thursday if nobody else has any other ideas.

I read somewhere that he motronic ecu will crank with no sparks, while gems would not even crank. But if you're right it should be something else because the dash display says nothing. The engine light also shows like usual at ignition position 2.

I did a fault code reading with a generic obd code reader, but it didn't register any fault codes. I just find that odd considering the car has said alarm fault since I bought it, and if it truly is immobilized surely it would show fault codes for that as well wouldn't it? Could the diagnostics not be working properly?

I'm going to give the dealer a call tomorrow and let him know the current situation with the car. I really want to figure this out but coughing up 5400 quid for a car and then have it not start the same week of purchase is unreasonable. Despite only owning the car for a mere week and it's given me nothing but troubles, I'd still prefer to get it running because first of all I'm a very stubborn person but secondly I know the engine is good and and the overall condition of the car is good, I mean for goodness sake I drove the car for two hours back home from the dealership and it ran perfectly.

Sounds like it's out of sync.

The later Thor models will crank if they are out of sync - only the GEMS won't crank.
A syncmate should sort that out, yes.

Mines a 2000 thor and won't crank. Just shows "engine disabled"
I'd be buying a nanocom in this situation if I was planning on keeping it.
Can you not take it back to the dealer to sort out?

Your issue and his are 2 different things.

If you get 'Engine Disabled' on the dash, and no cranking, then this is a sign that the immobiliser isn't switched off, and the it the BECM inhibiting the cranking. Either the BECM hasn't received a valid unlock code from the fob, (if locked with the fob) or hasn't detected the vehicle being unlocked with the key in the door (if locked with the key in the door) - or something else has happened, and the EKA hasn't been input correctly, or the vehicle has been unlocked and left standing, so the passive immobiliser has kicked in and re-immobilised the vehicle and it's waiting for an unlock code again to disarm it and allow starting.

If you get NO messages on the dash, but it will crank but not fire up, then on the Thor models, this is an indication of it not being in sync. No message on the dash shows that the BECM has disarmed the immobiliser, and will allow cranking. However, if the immobiliser code that the BECM sends to the engine ECU is mismatched, then the engine ECU will still inhibit firing the engine.

Earlier GEMS vehicles had the engine ECU respond the the BECM to tell it that it had accepted the immobiliser code (which is noted by the 'Check engine' light coming on in position II on a GEMS), and then the BECM will allow cranking. If it doesn't get a response from the engine ECU by the way of the CEL then it will inhibit cranking (but still won't show an 'Engine Disabled' as as far as the BECM is concerned it's not immobilised). The Diesel and Motronic ECU's are different in the fact that they DON'T respond to the immobiliser code being received - so the BECM has no way of telling if it's been accepted or not, which is why they will still crank, even if the code is incorrect - in these vehicles it's the engine ECU that if it's out of sync, that's stopping the vehicle from starting.

A syncmate will sort that out - but I agree, if someone is planning on keeping the vehicle for any period of time, then it's well worth investing in a Nanocom or similar, as it's better value for money in the longrun!

martyuk said:

Your issue and his are 2 different things.

If you get 'Engine Disabled' on the dash, and no cranking, then this is a sign that the immobiliser isn't switched off, and the it the BECM inhibiting the cranking. Either the BECM hasn't received a valid unlock code from the fob, (if locked with the fob) or hasn't detected the vehicle being unlocked with the key in the door (if locked with the key in the door) - or something else has happened, and the EKA hasn't been input correctly, or the vehicle has been unlocked and left standing, so the passive immobiliser has kicked in and re-immobilised the vehicle and it's waiting for an unlock code again to disarm it and allow starting.

If you get NO messages on the dash, but it will crank but not fire up, then on the Thor models, this is an indication of it not being in sync. No message on the dash shows that the BECM has disarmed the immobiliser, and will allow cranking. However, if the immobiliser code that the BECM sends to the engine ECU is mismatched, then the engine ECU will still inhibit firing the engine.

Earlier GEMS vehicles had the engine ECU respond the the BECM to tell it that it had accepted the immobiliser code (which is noted by the 'Check engine' light coming on in position II on a GEMS), and then the BECM will allow cranking. If it doesn't get a response from the engine ECU by the way of the CEL then it will inhibit cranking (but still won't show an 'Engine Disabled' as as far as the BECM is concerned it's not immobilised). The Diesel and Motronic ECU's are different in the fact that they DON'T respond to the immobiliser code being received - so the BECM has no way of telling if it's been accepted or not, which is why they will still crank, even if the code is incorrect - in these vehicles it's the engine ECU that if it's out of sync, that's stopping the vehicle from starting.

A syncmate will sort that out - but I agree, if someone is planning on keeping the vehicle for any period of time, then it's well worth investing in a Nanocom or similar, as it's better value for money in the longrun!

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Just one pedantic comment. It is not the engine ECU that is out of sync but the BECM. The code in the engine ECU never changes. But the one stored in the BECM copied from the engine ECU can get scrambled and can be rewritten by a Nanocom or use of a Syncmate..

@wammers that's not pedantry, that's accuracy. Quite different.
Sorry to be pedantic

I would expect nothing less from this forum.
I'm only trying to help the Original Poster out - and actually explain the difference between being 'Out Of Sync' and 'Engine Disabled'.. as the causes/remedies for these can be completely different. My apologies for not including every single detail to your liking.

martyuk said:

I would expect nothing less from this forum.
I'm only trying to help the Original Poster out - and actually explain the difference between being 'Out Of Sync' and 'Engine Disabled'.. as the causes/remedies for these can be completely different. My apologies for not including every single detail to your liking.

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No problem, but the difference has been explained by myself many times in the past. People just don't listen. You will have to possibly do it again several times in the future, may as well get it right eh.

My mistake, I'd read the op incorrectly. Sorry for any confusion!

Thank you everyone for the replies and the clarification regarding the engine immobilization and out of sync issues.

So it appears I'm suffering from a desynced ECU/BECM.

Now I called the dealer today and we agreed I would take the car to a mechanic and start from there. Funnily the local mechanic sounded a bit discouraged when I told him the car in question was a Range Rover -99 and jokingly asked whether my headlights were working. I told him the most urgent thing was to check whether the battery is bad or if it is simply being drained by the cars electronics. I also told him that I think the reason it doesn't start is because of the ECU and BECM being out of sync, probably as a result of the empty battery, and I got the impression that he was familiar with this. I will tow the car to the him on friday.

I've tried doing some more research myself about drained batteries and found some information about BECMs not going to sleep and that the remote alarm receiver could be the reason for this. I don't know if this is the most common thing but one thing I noticed when walking past the car once is this single beep from inside, maybe someone recognizes this?

I also know there has been a phone or something installed in my car because there's an antenna mounted on the rear left quarter glass and what is most likely a microphone on the left A-pillar, but I don't know how it is wired or if it could be a cause for battery drain, but either way I would have it removed since it's not something I use. Another thing I've noticed is that the fuel pump has been rewired directly to the battery instead of into the fuel pump relay in the fuse box, but I don't know the reason for this or if/how it affects the electronics or battery use.

Anyway, I will see how it pans out this weekend. In the meantime it has come to my understanding that owning a syncmate or this nanocom that has been mentioned a few times is probably a good idea if I want to keep this car for a while (which I do, provided I can get the possible battery drain problem worked out).

The nanocom is a bit more than I'm willing to spend on the car right now (there are other things on the car I would want to deal with first, like the climate control not functioning properly and the alarm fault message, but those things belong in another thread I think). I might get a syncmate still though, we'll see what happens after the workshop visit.

I am still curious to know the uses for a nanocom though (other than the out-of-sync issue) if anybody is happy to give any examples. I've also looked at the Faultmate MSV-2 and the Faultmate FCR. Do they have the same use as the nanocom and what is the difference between the two?

+1 on Nanocom. £150 for Syncmate will only fix one issue. You will probably need a Nanocom one to sort out the HEVAC system & figure out the alarm faults.

Battery drain is most likely RF receiver issues. Best short-term fix is to disconnect the antenna. You can still use the remote by holding near to the left rear window near the receiver. The BECM sleep test only takes 5mins.

Not sure where you are in Sweden, but there is a guy in Oslo with a Nanocom that might be able to help.

pwood999 said:

+1 on Nanocom. £150 for Syncmate will only fix one issue. You will probably need a Nanocom one to sort out the HEVAC system & figure out the alarm faults.

Battery drain is most likely RF receiver issues. Best short-term fix is to disconnect the antenna. You can still use the remote by holding near to the left rear window near the receiver. The BECM sleep test only takes 5mins.

Not sure where you are in Sweden, but there is a guy in Oslo with a Nanocom that might be able to help.

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I'll make sure to let the mechanic know about the remote receiver thing when I talk to him on friday. If it turns out removing the antenna solves the possible battery drain problem (I hope it's either that or a bad battery), I could buy the newest receiver eventually if I feel I need the remote range.

Yeah, I suppose a nanocom is more sensible... But it would have to wait a little while because I can't quite muster up that kind of money for the car just yet, especially for something that doesn't immediately and practically improve or fix something on the vehicle. I already spent a pretty large sum on a new car jack, the one my father had simply couldn't lift high enough so I could change to winter tyres. I'm moving soon so I'll be looking at spending some money on furniture and stuff too, so it would be unfortunate if the car would go out of sync again before I had some spare money for a nanocom, if that is what I would decide to get.

I am pretty far away from Oslo (6 hours) but it could be worth the trip if a nanocom is a requirement to get the hevac working properly again and be rid of the alarm fault message.



On the topic of the ECU/BECM sync problem, is this something that can happen randomly or usually when a battery goes flat?

if the fuel pump is wired directly to the battery it will run all the time and probably drain the battery quite a bit. Mods like that sound like someone didn't know what they were doing. Would be worth checking the fuse box for other issues like burnt tracks, contacts etc. Also, are there any other mods around the fuse box ? This is all standard electrical stuff, so as long as you're methodical, then fairly easy to trace & fix.

On the HEVAC, check the basics first, such as gas pressure, connections to sensors, water flow, etc.

martyuk said:

I would expect nothing less from this forum.
I'm only trying to help the Original Poster out - and actually explain the difference between being 'Out Of Sync' and 'Engine Disabled'.. as the causes/remedies for these can be completely different. My apologies for not including every single detail to your liking.

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Well it looked like a good comprehensive answer to me but what the bloody he'll do I know?

pwood999 said:

Battery drain is most likely RF receiver issues. Best short-term fix is to disconnect the antenna. You can still use the remote by holding near to the left rear window near the receiver. The BECM sleep test only takes 5mins.

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Disconnecting the antenna won't stop everything. best to wire in a second remote 12V switch as per @brianp38dse and then you can get the extortionate replacement RF receiver when you win the lottery.

Fuel pump direct to the battery? Don't like the sound of that as it won't cut out if you crash (he says having done the same to an Astra and driving it for years with it). On the Rangie there's a cut-out that has a reset switch behind the driver's kick-panel. Might just be the kill switch that was triggered and the PO didn't realise. Come to think of it, this is the Bosch system isn't it? Pretty sure the Astra SXi was Bosch too. On that the circuit that went to ground in order to pull the fuel pump in wouldn't drop to ground, hence why I soldered a wire on and connected that direct to the battery earth. Unfortunately it ran all the time the key was on after that. Not sure if you issue is the same but I'd check the fuel cut-off reset first.

Have you downloaded RAVE yet? You'll need that.

Hrodeberht said:

I'll make sure to let the mechanic know about the remote receiver thing when I talk to him on friday. If it turns out removing the antenna solves the possible battery drain problem (I hope it's either that or a bad battery), I could buy the newest receiver eventually if I feel I need the remote range.

Yeah, I suppose a nanocom is more sensible... But it would have to wait a little while because I can't quite muster up that kind of money for the car just yet, especially for something that doesn't immediately and practically improve or fix something on the vehicle. I already spent a pretty large sum on a new car jack, the one my father had simply couldn't lift high enough so I could change to winter tyres. I'm moving soon so I'll be looking at spending some money on furniture and stuff too, so it would be unfortunate if the car would go out of sync again before I had some spare money for a nanocom, if that is what I would decide to get.

I am pretty far away from Oslo (6 hours) but it could be worth the trip if a nanocom is a requirement to get the hevac working properly again and be rid of the alarm fault message.



On the topic of the ECU/BECM sync problem, is this something that can happen randomly or usually when a battery goes flat?

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This may be a strange reply but my friends RR had a problem with battery drain and took months to diagnose.It didn't go out of synch but would drain a good battery in10 hours.The problem turned out to be his neighbours house door bell was interfering with his alarm , constantly turning it on and off repeatedly as it scanned .Only solved when we stood near it and watched the doors locking/ unlocking repeatedly.probably a one in a million but that's what caused it

Joemac434 said:

This may be a strange reply but my friends RR had a problem with battery drain and took months to diagnose.It didn't go out of synch but would drain a good battery in10 hours.The problem turned out to be his neighbours house door bell was interfering with his alarm , constantly turning it on and off repeatedly as it scanned .Only solved when we stood near it and watched the doors locking/ unlocking repeatedly.probably a one in a million but that's what caused it

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No, the bell would have been on 433Mhz so same RF issue.