P38 alarm and immobilizer problems

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feyniriel

Active Member
Posts
87
Location
Finland
Have a 1999 2.5dse auto P38. For some weeks now the alarm has been going off at random. Sometimes the car doors are locked and someone goes to pull the door, the door will open and alarm goes off. Recently it has started going off for no reason and causing the battery to drain overnight. Few days ago it said "engine disabled, press remote". The key fob wasn't synced so we tried to enter EKA but car wouldn't take it, I'm wondering if it didn't work because it didn't ask for it or the door microswitches are broken?

There is a problem with the bonnet open sensor. When we drive off-road and the car shakes, open bonnet message comes on 10 times per minute. It is because in winter the bonnet froze shut and I had to yank it open, I assume I broke the sensor. Could it be just the open bonnet sensor causing the alarm to go off? Where even is the sensor, or how to go about fixing it?

Any ideas and suggestions are welcome. Trying to get a hold of an electrician, but everybody seems to be busy in this season.
 
Update: so yesterday the car started by changing the battery, after it got drained from the alarm. Today we brought a charged battery and it does not start. It's cranking, there's no fault codes on the dash other than the usual "set windows" that you get after disconnecting the battery. It's not even trying to fire, just cranking...
 
Update: so yesterday the car started by changing the battery, after it got drained from the alarm. Today we brought a charged battery and it does not start. It's cranking, there's no fault codes on the dash other than the usual "set windows" that you get after disconnecting the battery. It's not even trying to fire, just cranking...
Thae non starting is likely to be loss of sync between the BECM and the EDC, diagnostics needed to re learn the immobilisation code. A faulty bonnet switch can certainly trigger the alarm. If the door opened when it was supposed to be locked, then there is a problem with the latch mechanism, the micro switches, the out station or the wires between the A post and the door which could also cause alarm problems.
 
Have a 1999 2.5dse auto P38. For some weeks now the alarm has been going off at random. Sometimes the car doors are locked and someone goes to pull the door, the door will open and alarm goes off. Recently it has started going off for no reason and causing the battery to drain overnight. Few days ago it said "engine disabled, press remote". The key fob wasn't synced so we tried to enter EKA but car wouldn't take it, I'm wondering if it didn't work because it didn't ask for it or the door microswitches are broken?

There is a problem with the bonnet open sensor. When we drive off-road and the car shakes, open bonnet message comes on 10 times per minute. It is because in winter the bonnet froze shut and I had to yank it open, I assume I broke the sensor. Could it be just the open bonnet sensor causing the alarm to go off? Where even is the sensor, or how to go about fixing it?

Any ideas and suggestions are welcome. Trying to get a hold of an electrician, but everybody seems to be busy in this season.

Bonnet switches are in the holes the bonnet catches latch through. You can use a screwdriver to push them out the way and test them.

You might have RF interference if you don't have a generation 3 RF receiver. If you don't it will burn the locks out before too long. Or dump you sonewhere.
 
Thanks for the replies. I'm abroad with this car, trying to get a hold of a mechanic-electrician who would be able to mobilize the car again. Fortunately I know a mechanic who can remove the immobilizer, I think that's what I'm gonna do as soon as I'm able to drive the car again.

Is it only possible to resync the BECM with a nanocom? Are there any tests I can do to diagnose which parts might be at fault for triggering the alarm? The key locks all 4 doors at once and the engine light does come on briefly when trying to start the car.

I also read about the dancing locks syndrome somewhere, but I couldn't quite find out what it is, or if I've had it, because I've had what sounds like a similar issue with my door locks and was just wondering if it was related. Thanks!
 
Dancing locks are generally caused by worn microswitches in the latches. For example if the door open-close switch is worn, it can momentarily show door open when trying to lock it, so the BECM detects mislock. Equally a worn CDL switch will confuse things because the BECM thinks to door is unlocked when actully locked or vice versa.

Worn microswitches or latch mechanism can also make it hard to enter the EKA, because the BECM neess to see correct signals from both the CDL and Keyswitch microswitch when entering EKA.
 
Thanks for the replies. I'm abroad with this car, trying to get a hold of a mechanic-electrician who would be able to mobilize the car again. Fortunately I know a mechanic who can remove the immobilizer, I think that's what I'm gonna do as soon as I'm able to drive the car again.

Is it only possible to resync the BECM with a nanocom? Are there any tests I can do to diagnose which parts might be at fault for triggering the alarm? The key locks all 4 doors at once and the engine light does come on briefly when trying to start the car.

I also read about the dancing locks syndrome somewhere, but I couldn't quite find out what it is, or if I've had it, because I've had what sounds like a similar issue with my door locks and was just wondering if it was related. Thanks!
There may be diagnostics other than Nanocom that can re-sync the BECM/EDC. you cannot physically remove the immobiliser but it can be disabled in the BECM using Nanocom, the EKA code requirement can also be turned off with both turned off, the car can be operated with just the key blade. I run both my P38's like that.
 
There may be diagnostics other than Nanocom that can re-sync the BECM/EDC. you cannot physically remove the immobiliser but it can be disabled in the BECM using Nanocom, the EKA code requirement can also be turned off with both turned off, the car can be operated with just the key blade. I run both my P38's like that.
I hope I can find a diagnostic tool that would re-sync the BECM. We'll try to call a bunch of electricians tomorrow to see if anybody would have a tool that can do this... I hope I can get the car running soon as we drove 2000km abroad and it's our daily driver, left us stranded...
 
The electrician came today with his Delphi diagnostic tool. His reader could not connect with the ECU. The diagnostic tool said "wait, trying to establish connection with ECU... cannot establish connection, unplug and reconnect". It did have power from the OBDII, it could see the voltage of the battery, but nothing else. He went through the car, checked the fuses, checked the crankshaft sensor, checked passenger footwell computer (not sure what it's called?) and its connections - it was dry, checked ignition switch, tried disconnecting white connector closest to the engine bay from the fusebox under the passenger seat, tried starting the engine with spray to see how it behaves, it did ignite and fire for a few seconds, then died off so clearly the fuel intake is disabled from the engine.

This electrician was not an expert in LandRovers and concluded that there must be water damage to some of the wires (which I admit, there is a leak in the footwells and ceiling lights from somewhere) and recommended we tow the car to his workshop to get it taken apart and every wire inspected. I asked him if he does it and manages to fix a corroded wire, connection, sensor, whatever it could be, will he be able to mobilize the engine if the BECM needs to be resynced to the ECU? He said he has the tool for it but he did not seem to believe it was immobilized. From what I've gathered, this electrician probably did not really have a clue about what's wrong.

So we called a knowledgeable LR guy with a Nanocom for TD5, who said that the problem is most likely that it's out of sync and when that happens, the BECM cuts power from the ECU and doesn't let a "normal" diagnostic tool to read it. He doesn't have the nanocom unlock for P38, so he couldn't help us but suggested we get a SyncMate. Something we also read was that if the engine light doesn't come on while turning the key in ignition, it's unsynced. The engine light does come on briefly though. What does this mean??

We'll call some more Land Rover services tomorrow but in Romania they seem to be really scarce and nobody really has the right diagnostic tools for P38s. Does anybody have a clue on what to do next? Could a nanocom really fix this issue? It's quite costly for such a random issue with a car that I'm not sure I'll want to keep after this experience, but then again we have a TD5 Defender and Disco2 in the family, so it could come in use in the future. However I don't really understand which nanocom to get in that case, does the Discovery TD5 work for the Defender and vice versa? Which unlock is the correct one for a 2.5dse 1999 P38?

Thanks for your replies guys, this forum seems to have better advice than real life mechanics and electricians. I contacted the mechanic from my country who is supposed to be an expert on P38 and he told me I should just set fire to it...
 
The electrician came today with his Delphi diagnostic tool. His reader could not connect with the ECU. The diagnostic tool said "wait, trying to establish connection with ECU... cannot establish connection, unplug and reconnect". It did have power from the OBDII, it could see the voltage of the battery, but nothing else. He went through the car, checked the fuses, checked the crankshaft sensor, checked passenger footwell computer (not sure what it's called?) and its connections - it was dry, checked ignition switch, tried disconnecting white connector closest to the engine bay from the fusebox under the passenger seat, tried starting the engine with spray to see how it behaves, it did ignite and fire for a few seconds, then died off so clearly the fuel intake is disabled from the engine.

This electrician was not an expert in LandRovers and concluded that there must be water damage to some of the wires (which I admit, there is a leak in the footwells and ceiling lights from somewhere) and recommended we tow the car to his workshop to get it taken apart and every wire inspected. I asked him if he does it and manages to fix a corroded wire, connection, sensor, whatever it could be, will he be able to mobilize the engine if the BECM needs to be resynced to the ECU? He said he has the tool for it but he did not seem to believe it was immobilized. From what I've gathered, this electrician probably did not really have a clue about what's wrong.

So we called a knowledgeable LR guy with a Nanocom for TD5, who said that the problem is most likely that it's out of sync and when that happens, the BECM cuts power from the ECU and doesn't let a "normal" diagnostic tool to read it. He doesn't have the nanocom unlock for P38, so he couldn't help us but suggested we get a SyncMate. Something we also read was that if the engine light doesn't come on while turning the key in ignition, it's unsynced. The engine light does come on briefly though. What does this mean??

We'll call some more Land Rover services tomorrow but in Romania they seem to be really scarce and nobody really has the right diagnostic tools for P38s. Does anybody have a clue on what to do next? Could a nanocom really fix this issue? It's quite costly for such a random issue with a car that I'm not sure I'll want to keep after this experience, but then again we have a TD5 Defender and Disco2 in the family, so it could come in use in the future. However I don't really understand which nanocom to get in that case, does the Discovery TD5 work for the Defender and vice versa? Which unlock is the correct one for a 2.5dse 1999 P38?

Thanks for your replies guys, this forum seems to have better advice than real life mechanics and electricians. I contacted the mechanic from my country who is supposed to be an expert on P38 and he told me I should just set fire to it...
I would put money on it being loss of sync. Water in the car will certainly give you trouble at some point even if it's not the source of you current problem. Nanocom for the P38 diesel is what you need, I never travel in the P38 without carrying diagnostics. Software modules can be added for other Land Rover vehicles, check if they are available for your vehicles at www.blackbox-solutions.com.
The ECU under the passenger seat, assuming your car is left hand drive, is the BECM, (body electronic control module)
 
Thanks for your reply datatek. Is it possible to take the ECU and BECM out of the car and send them to a LR workshop to get them resynced or does the whole car need to be towed there?
 
Loss of sync does not stop diagnostics. However, it isn't OBD compliant. BMW INPAR software will work on the diesel. After that you're looking at Syncmate, Nanocom, Faultmate or possibly Hawkeye or Lynx. They will need the connectors behind the footwell and the OBD socket to work though, so water ingress could complicate matters.

If it has lost sync then the code in the engine management system needs to be read and then written to the body electrical control module.
 
Loss of sync does not stop diagnostics. However, it isn't OBD compliant. BMW INPAR software will work on the diesel. After that you're looking at Syncmate, Nanocom, Faultmate or possibly Hawkeye or Lynx. They will need the connectors behind the footwell and the OBD socket to work though, so water ingress could complicate matters.

If it has lost sync then the code in the engine management system needs to be read and then written to the body electrical control module.
Loss of sync does not stop diagnostics with a Nanocom or a "normal" diagnostics tool? Because I've read that with a "normal" tool the BECM won't allow it to read the ECU, and that's why supposedly the Delphi diagnostic wasn't making connection. What did you mean by it not being OBD compliant?

Will BMW INPAR be able to resync it and delete the immobilizer? I fear that something such as a Nanocom is needed to be able to access the engine management.
 
Loss of sync does not stop diagnostics. However, it isn't OBD compliant. BMW INPAR software will work on the diesel. After that you're looking at Syncmate, Nanocom, Faultmate or possibly Hawkeye or Lynx. They will need the connectors behind the footwell and the OBD socket to work though, so water ingress could complicate matters.

If it has lost sync then the code in the engine management system needs to be read and then written to the body electrical control module.
BMW INPAR works on a P38? Not heard of that before.
 
There are workshops offering to disable the immobiliser if I send the ECU to them for 250€... Is it possible to just disable it without mobilising and resyncing it first? The mechanic said immobilizer cannot be disabled through Nanocom for this ECU... Really considering getting the Nanocom for P38, but what if it won't fix the issue? Nanocom is quite costly... I don't suppose it's possible to return it and get money back if it doesn't work?
 
Loss of sync does not stop diagnostics with a Nanocom or a "normal" diagnostics tool? Because I've read that with a "normal" tool the BECM won't allow it to read the ECU, and that's why supposedly the Delphi diagnostic wasn't making connection. What did you mean by it not being OBD compliant?

Will BMW INPAR be able to resync it and delete the immobilizer? I fear that something such as a Nanocom is needed to be able to access the engine management.
The P38 does not comply with the OBD standard so only specialised diagnostics will work. There is no possibility of doing anything with what you call "normal" diagnostics. The BECM cannot stop diagnostics from reading the EDC values.
As far as I'm aware, BMW INPAR doe not work on the P38.
There are very few places that could re-sync the EDC/BECM out of the car, Rick the Pick in the UK is one.
If the car is to be towed, do not forget to insert fuse 11 in the fuse box under the seat to select transfer neutral or you will wreck the gearbox. I doubt many LR dealers still have the equipment to re-sync the EDC/BECM now.
The best solution is to buy a Nanocom, it will pay for itself in no time, in fact it will probably n ot cost much more than the cost of the tow and the LR dealer charges..
 
There are workshops offering to disable the immobiliser if I send the ECU to them for 250€... Is it possible to just disable it without mobilising and resyncing it first? The mechanic said immobilizer cannot be disabled through Nanocom for this ECU... Really considering getting the Nanocom for P38, but what if it won't fix the issue? Nanocom is quite costly... I don't suppose it's possible to return it and get money back if it doesn't work?
Btw the mechanic was not going to disable the immobiliser with nanocom but manually with a laptop.. I don't know anything about these things and my fiance who's a good mechanic is also at a loss.
 
There are workshops offering to disable the immobiliser if I send the ECU to them for 250€... Is it possible to just disable it without mobilising and resyncing it first? The mechanic said immobilizer cannot be disabled through Nanocom for this ECU... Really considering getting the Nanocom for P38, but what if it won't fix the issue? Nanocom is quite costly... I don't suppose it's possible to return it and get money back if it doesn't work?
The immobiliser is actually not an immobiliser as such, what happens is that the BECM sends a mobilisation code to the EDC. It's not something that can be physically removed but it can be put into a mode where it happens automatically without the need for the FOB to open the car.
You cannot buy Nanocom on a sale or return basis and you are bound to need it for other P38 problems, you cannot keep these old cars on the road without diagnostics.
 
The P38 does not comply with the OBD standard so only specialised diagnostics will work. There is no possibility of doing anything with what you call "normal" diagnostics. The BECM cannot stop diagnostics from reading the EDC values.
As far as I'm aware, BMW INPAR doe not work on the P38.
There are very few places that could re-sync the EDC/BECM out of the car, Rick the Pick in the UK is one.
If the car is to be towed, do not forget to insert fuse 11 in the fuse box under the seat to select transfer neutral or you will wreck the gearbox. I doubt many LR dealers still have the equipment to re-sync the EDC/BECM now.
The best solution is to buy a Nanocom, it will pay for itself in no time, in fact it will probably n ot cost much more than the cost of the tow and the LR dealer charges..
Thanks for your reply! Does the power need to be on (key in 2nd position in the ignition and battery connected) while it's getting towed, to be able to have the transfer case in neutral with the fuse?
 
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