RangeRovers.net Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Has anybody successfully water proofed the becm & the other electrical stuff under the front seats ??
Are there any harness extensions available to remount the becm higher ??
I have a very wet becm at the moment , water was a little deeper than we thought !!
The whole system went crazy when it got wet !!
Been through deep water before , but this time I got stuck ...
Any help would be great , thanks Jeff
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
139 Posts
I don't think it's possible to really waterproof BeCM due to the nature of the connectors used. They are not waterproof. Theoretically you could relocate BeCM higher, but there isn't a good place for it that I can think of. the area under dash gets water leaks from the sunroof. It's marginally better, saves you from water in case you drove into a puddle too deep, or in case your heater core o-rings leaked, which they eventually always do.

A better idea would be to rig the ECU to run without BeCM. Everything else that the ****' gadget controls is either non-essential equipment or can be controlled by other means.
 

·
Super Moderator
Joined
·
2,310 Posts
Dry the BeCM very carefully (off the car) then buy a lot of cable and connectors to extend the 17 multiways connections and bolt the BeCM to the back of the seat or even hang it from the roof.
 

·
LEGACY VENDOR
1995-2002 Range Rover P38A
Joined
·
4,220 Posts
I've seen a lot of people talk about moving the BECM, but never seen a finished product. Seems like most people get put off when they see how many wires there are to extend, of all different thicknesses.

I made a BECM tester for when I repair them, and terminating the ends of all of them - probably near on 200 wires - on the bench took long enough, yet alone doing it in the vehicle.

Regarding the BECM getting wet though...

The lower, logic board is actually mostly coated with a protective lacquer. As Richard_G says, remove the whole BECM from the vehicle. I'd wash off the logic board with clean water, and then put it in a tray/bag of rice for a couple of days to try and dry it out.

Possibly do the same with the power board, but they aren't coated, so it could be possible it's been damaged.

However, if the logic board works OK still, you can swap it into another case with a working power board (as long as it's the same trim level - low line of high line, designated by a "L" or "H" on the sticker on the fusebox), and get the vehicle running properly again that way, without having to have anything reprogrammed.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
1,433 Posts
A number of people have simply cleaned out the BECM after flooding and dried it off and it has been OK. They are quite robust.
I remember also a few owners used sealant around the BECM case and plugs and the BECM overheated as a consequence.
 

·
Registered
Joined
·
22 Posts
Curious about the above statement: "A better idea would be to rig the ECU to run without BeCM. Everything else that the ****' gadget controls is either non-essential equipment or can be controlled by other means."

I would like to try this. What's involved? Thanks.
 

·
Super Moderator
Joined
·
2,310 Posts
A complete rewire of the car. The BeCM controls everything body related, starting, charging, lights, wipers, instruments, locking, windows, and in conjunction with other controllers, ABS, heating, gearbox, transfer case, etc. Or just go out and buy a Series 1 Discovery.....
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
139 Posts
A complete rewire of the car. The BeCM controls everything body related, starting, charging, lights, wipers, instruments, locking, windows, and in conjunction with other controllers, ABS, heating, gearbox, transfer case, etc. Or just go out and buy a Series 1 Discovery.....
Windows and locking can be controlled by any decent aftermarket system, which are abundant and cheap. ABS is controlled by its own ECU. BeCM gives you OBDII functionality for diagnosing ABS faults, which is arguably non-essential. Gerabox is also controlled by its own ECU, with BeCM providing OBDII diagnostic functionality. Starting and charging can be done using a couple of relays so long as you get the ECU to cooperate. You can keep the Mortronic ECU happy by wiring an EWS 3.3 Emulator to respond to the mobilization rolling code on the serial line instead of BeCM. There is one leg you need to cut on the motronic chip, couple of wires to solder and one chip to add. It's the same system as late 90s BMWs with Motronic 5.2. The things that are truly controlled by BeCM and are difficult to get to work without it are power seats and the instrument cluster. So, while the BeCM has its tentacles everywhere, most systems in a P38 don't need it for them to work.

The biggest problem with BeCM is due to the fact that you can't easily swap a used replacement because for the POS security system. If you were to defeat the security system somehow, the BeCM becomes a non-issue, because used ones are abundant and inexpensive.
 

·
Premium Member
Joined
·
1,344 Posts
^^ that's pretty much a complete rewire, including adding aftermarket control systems for which there will we be little or no support...
Doesn't sound like an upgrade to me.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
139 Posts
I think we should just exorcise the security system that would allow us to swap ECUs and BeCMs without any hurdles. In my mind that's the most effective way to tackle the problem. I think the first order of business should me modifying the Bosch ECU to run standalone, without BeCM. This way the truck would be at least run, absent a genuine mechanical problem. I can live without a functional instrument cluster if I am "limping back home".

Enabling proper diagnostics without paying more than the truck is worth for a scan tool would be a nice bonus to have.
 

·
Super Moderator
Joined
·
2,310 Posts
and why do you feel the need to swap ECUs? For GEMS there is a standalone option but not for Bosch, probably because every other car that uses the Bosch Motronic ECU also has similar security features. Difference is, owners of BMW, Saab and others using a virtually identical system don't feel the need to start swapping bits and blaming the design for their own ineptitude. There's nothing wrong with the security system, it does it's job perfectly.

Treat it like you would a woman, by the time she's asked you to do something 3 times and you still haven't, you're likely to find prviledges withdrawn. A P38 is no different, when it starts locking and unlocking itself then do something about it or it won't let you play any more.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
139 Posts
and why do you feel the need to swap ECUs? For GEMS there is a standalone option but not for Bosch, probably because every other car that uses the Bosch Motronic ECU also has similar security features. Difference is, owners of BMW, Saab and others using a virtually identical system don't feel the need to start swapping bits and blaming the design for their own ineptitude. There's nothing wrong with the security system, it does it's job perfectly.

Treat it like you would a woman, by the time she's asked you to do something 3 times and you still haven't, you're likely to find prviledges withdrawn. A P38 is no different, when it starts locking and unlocking itself then do something about it or it won't let you play any more.
Essentially, I need to swap the ECUs because they are poorly designed and fail often, rendering the truck into a piece of yard art. And I prefer to have my equipment in running condition.

In the BMW world the security system exorcism is quite common, actually. People often modify these cars and they need to swap ECUs.

The P38 BeCM is one of the worst designs that I have seen in automotive electronics in a very long time, and I have seen more than a few. P38 rovers are leakers, both from the roof area and from the heater core and infamous o-rings. Unlike proper automotive electronics that are able to survive in the engine compartment (a number of Jeeps, Cummins diesels, GEMS and Bosch Rover ECUs, etc.) and inside the transmissions (ZF 6Hp, GM 6L80 and derivatives) the silly gadget that the Rover engineers came up with can't survive even a reasonably safe place under the seat. It relies on airflow for cooling, so it can't be sealed. Which is beyond ridiculous for embedded electronics. What were they smoking?

Now, if that wasn't bad enough, the clever and resourceful Rover engineers managed to come up with a finicky security system that is unable to cope with things that are "surprise, surprise" bound to happen on a well used car, like failed microswitches, worn out latches, loose grounds and corroded contacts in the downstream wiring looms.

What possessed them to put the power board into the same case as the logic board? Relays can wear out, they can burn out too. Wiring problems happen, it's a fact of life which Rover engineers were apparently blissfully unaware of. A much better design would have been a self-contained sealed automotive-grade module located in a place where the chances of water damage are slim. And a relay and fuse box external to said module in a place where it would be readily accessible. Which is how it was always done, ever since automotive electronics became a thing.

From a systems design standpoint, channeling everything through one centralized electronics module virtually guarantees failure. Because, as I said before, wiring problems, short circuits, loose ground and other such problems happen. Had the system been designed by someone remotely competent, each subsystem would have had its own standalone ECU, with the rest being able to continue to work without it. If I have an issue with rear window wiper motor, or a sunroof, or some other non-essential equipment, the last thing I want is for it to cause the BeCM to freak out and shut the car down, rendering it into a piece of yard art.

Land Rover uses a Bosch Motronic 5.2.1. It uses the same rolling-code immobilization implementation as many a BMW with 5.2 motronic and various outher European cars. EWS 3.3 emulator can deal with this problem, it has been done numerous times in the BMW world. You need to cut or de-solder one leg of the chip from the ECU logic board, find a way to secure the emulator chip and solder a handful of wires. Essentially, you are moving this whole security communication inside the Bosch ECU, which unlike the BeCM is properly designed and lives just fine in the engine compartment. No more interactions with BeCM will be required for the car to run. I don't know if you can wire an EWS 3.3 emulator outside of the ECU. I have never seen it done, but it doesn't mean that it is impossible. It only means that I have never seen it done.
 

·
Super Moderator
Joined
·
2,310 Posts
Essentially, I need to swap the ECUs because they are poorly designed and fail often, rendering the truck into a piece of yard art. And I prefer to have my equipment in running condition.
So why are you blaming the BeCM when you are now saying that the Motronic is poorly designed and fails often?
Land Rover uses a Bosch Motronic 5.2.1. It uses the same rolling-code immobilization implementation as many a BMW with 5.2 motronic and various outher European cars. EWS 3.3 emulator can deal with this problem, it has been done numerous times in the BMW world. You need to cut or de-solder one leg of the chip from the ECU logic board, find a way to secure the emulator chip and solder a handful of wires. Essentially, you are moving this whole security communication inside the Bosch ECU, which unlike the BeCM is properly designed and lives just fine in the engine compartment. No more interactions with BeCM will be required for the car to run. I don't know if you can wire an EWS 3.3 emulator outside of the ECU. I have never seen it done, but it doesn't mean that it is impossible. It only means that I have never seen it done.
So why not try it? The Motronic is made by Bosch and supplied to numerous European manufacturers, the only difference being the programming. So if it is possible to remove the security on a Motronic programmed to run a BMW then why is it so difficult to do the same on one programmed to run a P38?

Don't forget when the P38 electronics were designed. The car was released in 1994 in the UK so would have been at the design stage at least a couple of years before that. It was state of the art for the time when other manufacturers were still using discrete relays and fuses. It was one of, if not the, first car to have a centralised body control module. OK, so the security system may get confused if things start to wear but we are talking 15 -20 year old vehicles when a manufacturer designs for a 10 year design life. The fact that they are still working with minimal maintenace at twice that age is a testament to how well designed it is, not how badly.
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
139 Posts
So why are you blaming the BeCM when you are now saying that the Motronic is poorly designed and fails often?
Motronic 5.2 is actually a good, reliable system. Earlier versions, particularly the ones fitted to early 80s vintage Porsche and BMWs were not particularly reliable in my experience. When it comes to P38, the Motronic ECU functions exactly the way it should. It's the BeCM that fails, causing the Motronic to immobilize the truck. It's rarely, if ever, a problem with BMWs, because they have a separate ECU that handles security. This security ECU is only connected to a minimal number of things it actually needs to be connected to, so it is very reliable. I suspect that BMW ownership of Rover from 1994 until 2000 was the reason as to why GEMS was replaced with Bosch and why the replacement electronics are so similar to those in BMW.

So why not try it? The Motronic is made by Bosch and supplied to numerous European manufacturers, the only difference being the programming. So if it is possible to remove the security on a Motronic programmed to run a BMW then why is it so difficult to do the same on one programmed to run a P38?
My guess is that there are a lot more BMWs than P38 Range Rovers out there. Plus, it seems that entry-level 3-series BMW owners are a lot more inclined to mess with their cars. I don't think it's different, I think that no one other than Mark Adams of tornado systems has bothered with this. I'll definitely try it when I get the time. I just need to get my P38 ready for winter first, because I don't want to end up driving a supercharged Jag on wide 18-inch tires in the snow once again.

Don't forget when the P38 electronics were designed. The car was released in 1994 in the UK so would have been at the design stage at least a couple of years before that. It was state of the art for the time when other manufacturers were still using discrete relays and fuses. It was one of, if not the, first car to have a centralised body control module. OK, so the security system may get confused if things start to wear but we are talking 15 -20 year old vehicles when a manufacturer designs for a 10 year design life. The fact that they are still working with minimal maintenace at twice that age is a testament to how well designed it is, not how badly.
I have a couple of Jaguars of the same exact vintage as P38 Range Rovers. One is a 1996 XJR supercharged and the other one is 2000 XK8. The Jaguars have their flaws (thou shalt not let the water damage the GEMS 6 ECU and wiring harness) but their electronics are infinitely more reliable than those of the P38. And these are cars that were not only manufactured around the same time, they were made in the same country and they fall into the same premium/expensive category. So the comparison is entirely fair, and not in favor of the Rover engineering. A centralized body controller is a fine idea, provided it is reliable and does not immobilize the car. Integrating security into it was a mistake. The more wires you connect to an ECU the more likely it is to burn out. Connecting everything to one ECU that is capable of immobilizing the truck is the ultimate version of putting all eggs in one basket.
 

·
Super Moderator
Joined
·
2,310 Posts
I suspect that BMW ownership of Rover from 1994 until 2000 was the reason as to why GEMS was replaced with Bosch and why the replacement electronics are so similar to those in BMW.
There was nothing wrong with the GEMS system except it could only be made to be OBD compliant which became mandatory in the US in 1996. In 2000 OBD2 compliance became mandatory in Europe and the GEMS unit would have needed a complete redesign to allow it to meet that spec, so it was far easier to use a system that was already in production that did meet the spec. As BMW were already buying millions of Motronic units from Bosch for their other cars, it made sense to adopt that option. Even without the BMW influence, something would have needed to be done. For instance, GEMS, or at least a European spec GEMS, does not give misfire codes so you don't get the P0300 - P0308 codes that you do get on a Motronic, no matter how badly an engine is running.
 
1 - 16 of 16 Posts
Top