Thanks guys... It's always nice to meet other P38 owners in person!
I just really do it because I enjoy tinkering... I've done BECM unlocking for a number of owners now where their BECM has gone into an alarmed mode - I even had one sent to me from NZ for unlocking at the local dealers over there wanted the owner to pay silly money for them to basically swap parts about to try and fix the problem. The fact that these vehicles are getting older, and a lot of independant LR garages don't know a lot about the electrical side of them intrigued me, and kinda wanted to know what all the fuss was about and why they were always regarded so badly by garages, when they aren't actually that difficult to work on and it's kind of just grown from there. The BECM stuff is more because it seems to get commonly blamed for a lot of problems and silly amounts quoted to fix/replace it. In my experiences a lot of problems (not all, but a fair chunk of them) are actually due to external influences (broken wire, dodgy switch - door latch microswitch failure etc) that have either caused the BECM to go into an alarmed state and flatly refuse to do anything, or the external input is confusing it and causing strange things to happen. Granted, they do occasionally actually fail too!
Well done Marty!
That is exactly what I mean by reverse engineering!
I have spent the last year doing the same to Porsche alarm control units in current model Porsche cars. It is a bit of a pointless and thankless task in some ways.. I already have the Porsche kit to reprogram them, so it has no monetary motive, and I can't help others by publishing how to decrypt the megamos security, partly because Megamos VW and Porsche have already sued a couple of students for doing just that as part of their dissertation, but also because it would make every Porsche out there less secure! So although I have spent a year doing it without thinking too much about why I have been doing it, the only reason I can think of why I did it was for the thrill of being me versus the software and electrical engineers who designed it not to be cracked.. And because I do love a good tinkering session!
Have you figured out how to knock out the diesel engine management computer from waiting for an immobiliser code? (which I presume it does?).. I would be a lot happier if I could get this gone from my BECM and from the engine management, as my lack of faith in the BECM is the one thing which knocks my confidence in my P38.. I would rather have the immobiliser gone from the BECM and fit something like a Toad cat-1 alarm and immobiliser to it for the immobiliser and remote locking functions.
What are your motives? Just tinkering? A business idea, or are you thinking of posting a common electrical faults and how to fix them guide?
When you get a new key from LandRover, does it come with a barcode with digits they program in with their computer to the BECM to code the key, or do they put it into a learning mode and then just use the key?
Very interesting what you say about the Porsche system - I've been looking into some of the P38 key fob transmissions and trying to figure out how it 'encrypts' the transmission, then be able to 'decrypt' it to check the fob identity and the likes as I get a lot of people ask me if I am able to tell them what key # they have, which a tester would be able to do. I have an idea thanks to another member about roughly how it does the sending of information, but without knowing the exact details on how it does it, I'm pretty much dead in the water on that. I am hoping to collaborate on some BECM bits and as I mentioned above - try and get a key fob tester made so that I can then be able to check key identities against what is stored in the BECM if I have on the bench to then be able to identify the fob and if it should actually work with the vehicle.
The diesel immobiliser code is only sent by the BECM when the vehicle is unlocked and disarmed. I have read of ways of being able to turn that off in the diesel ECU, so that it doesn't require an immobiliser code to be sent - but that is done in one of the EEPROMs in the DDE ECU rather than at the BECM end. It might be something I will look into at some point, as I have a couple of spare DDE ECU's around somewhere!
When a new key comes from Land Rover, it is pre programmed at the factory and is programmed to the lockset barcode which they have on file against the vehicle VIN number. When it arrives, all that needs to happen is to sync the key to the vehicle and it will work. Some people have found out after buying a new key that it doesn't work because the BECM has been changed (and thus is programmed to a different lockset). The lockset barcode sadly doesn't come with the new key fob - but it is usually obtainable direct from Land Rover as it is noted on their database with the rest of the vehicle details. If that is obtained, then it can be sent to BBS to be translated into the fob codes which are stored in the BECM - so you can reprogram a lockset to the vehicle if needed. though you can't use say a key 1 from one lockset and a key 2 from another - all keys have to be from the same lockset to work with the vehicle.
My motives... pretty much just tinkering - I'm a self-confessed P38 enthusiast, and love them for some reason! I like the idea of being able to help owners keep them on the road at a reasonable cost and hope I can offer more of a detailed/specialist P38 service to people who have been told by a local garage that it's going to be silly money to fix, when it is really a simple problem! It's not really a business idea - I do it as a hobby outside of my real job, and any money I do make usually goes into acquiring more bits, or a bit towards the maintenance of my own P38. Other than BECM bits I refurbish door latches, repair window switchpacks, refurbish EAS compressors (well the occasional one as there are loads of places that do EAS bits!), and have a repair for the dead HEVAC LCD pixels. I'm also thinking of offering a HEVAC overhaul service which includes the LCD Pixel repair, upgrade of the screen backlight to LED, and an option to do it as white LED aswell. I also have done LED dash/switch conversions and other projects which are in the pipeline are a replacement for the commonly faulty DSP amplifier using the older and more robust individual door amplifiers, and also have been working on a replacement for the EAS driver pack. I also want to work on modifying a BECM power board to then be able to use LED lamps in all the indicators/brake lamps etc without generating a warning error - but that's a bit further off!
I have already done a number of writeups on various electrical bits, most of which are posted on Rangerovers.net (my username there is marty_nz if you want to have a look). Previous writeups include door latch microswitch tests, how to repair dodgy window switches, wiring pinouts for the DSP system all collated and described for functions in a spreadsheet, a writeup on LED conversions for the instrument cluster and dash switches, and one on my upgrade of the factory navigation system to a 7" touchscreen unit, which I've tried to make look as 'factory' fitted as possible.
I don't think any of it is ever going to become a fully fledged business, but it's nice to have 'on the side' and keeps me out of trouble when I am at home.... anything extra I make doing it this year is going to be going into restoring a couple of other P38's I bought last year - as they were 'spares or repair' but far too nice (in my mind) to scrap... An 'R' reg with 83K and an 'X' reg Vogue with 89K. They both need a LOT of work, but I like a challenge! Nothing much is going to be happening project wise for the next couple of months as I'm away a lot with work, and don't have a lot of spare time to work on anything P38 related until the end of June now - so I'll just have an online presence until then, and hopefully over summer can get my DSP replacement project tested (it's built already)
Marty