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1995-2002 Range Rover P38A
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Discussion Starter #1
Hi folks

While driving home one night my dash instruments all dropped as if I'd turned off the car, all illumination went out and I got a continous bleeping. The car still drove fine and as it was wet & cold and I had my young kids with me I decided to continue driving the further 4 miles to home (my headlights still worked). The only item on the dash working was a SRS light which appears to cycle continuously from high to dim.

Once I turned off the engine I got the fuse 6 and gearbox alarms, but I've checked every fuse in the engine bay and underseat fuseboxes but they are all fine. After some searching on here I started through the 'electrical sticky' sheet and right away found my alternator was gone - 14V at idle and 16V and rising as I started increasing the revs. I've now fitted a 2nd hand alternator and it's sitting at a steady 14.06V across the rev range - my rev counter is still not working.

When the ignition is on the car keeps on bleeping a sequence of 3 long then 5 short bleeps, (or 3 long delays with 5 short delays between bleeps). I'd expect this is some sort of code, but I can't find any information on it.

One good thing is that the car still starts and appears to run fine, but I don't think the gearbox is changing up the range as it should as it sounds like it is in a single high gear all the time - I'm limited to testing this properly as it involves driving on the road which isn't too clever at the moment.

I have noticed that the fan controls which while not illuminated, the display does work and changes as it should. But when I activate any heater then the button illuminates then goes out (so unable to go through the electrical sticky properly). I can hear the fan running as usual, but when I press the brake pedal the fan slows to a stop, then returns when I lift the brake pedal.

Once I turn the engine off again then the dash warning area illuminates again so I can read gearbox fault, and sometimes fuse 6 and I think fuse 17(?).

If this sounds familiar to anyone then I'd love to hear if there's a fix.

Thanks
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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4,219 Posts
Hi there,

Unfortunately I think your BECM has taken a dive on you. This is the brains of the vehicle, and if damaged, will cause all sorts of things to not work. If you put in your information where you're located, then we can suggest things which are relevant to your area etc...

I have had this exact problem on my first RR, which was a 1995 4.6HSE. Someone had replaced the fuse box at some point and pinched one of the main wires to the BECM between the fuse box and the chassis. The insulation had worn through over time, and it started arcing, causing irreversible damage to my BECM. I had to get a replacement one put in, and fixed the power cable so it couldn't happen again.

However, before you go ordering a new BECM, there are a couple of things you can do... check the underbonnet fuse box. This is where the BECM gets its power, and a lot of the functions are powered from. If any of the relays are brown on top, and there's discolouration and cracking under them - then it's time for a new fuse box to start with. They get brittle with age, and from the heat under the bonnet. Also, due to heavy loads put on relays (namely the heater blowers as they age, as pollen filters get clogged etc), it can start to wear/burn the tracks out inside the fuse box PCB.

Nest step would be to check the wiring to the BECM, for any chafing, or signs of arcing or damage (like in my case where the power cable had been trapped).

If this all looks ok, then it's time to remove the BECM from the vehicle, and open it up for inspection. There are lots of details, and pictures on doing this on the main rangerovers.net site, and on the forum... but the basics are:

Disconnect battery completely
Unbolt RHS set (Drivers UK, Passenger US) **you will need a Torx T50 bit for this **
Either roll the seat back, so it's leaning on the back seats, or carefully remove it from the vehicle
Unplug all the connections from the BECM (the main power wires require a 10mm socket from memory...
Undo (again from memory) 3 nuts that hold the BECM into the vehicle - 10mm IIRC
Remove BECM

Once it's inside and you're comfy, you'll need other Torx bits (T10/T15) to take the top cover off. Once open, you should be able to see if there's any damage/corrosion to the top power board... if there is, then you've found the problem..

You might need to send the BECM away (to Scotty in the US, or I think Rick-the-Pick in the UK) to get them to look at the BECM properly, or clone your vehicle details onto a substitute BECM for replacement back into the vehicle.

If there is signs of moisture or corrosion in the BECM, then it would be wise to try and find the source of water... generally RHS footwell carpet (or especially the foam under the carpet) will be wet is the heater core O-rings are leaking.. Also blocked sunroof drains can cause water ingress down the sills under the bottom trims in the doorways.. Oh and improperly fitted/missing pollen filters can cause water ingress up front too.. Ask me how I know!!

Oh, and regarding behing able to start car/drive but no gear changes etc... it's the inbuilt failsafe... if there is a major issue, then the BECM will still retain functions required for safety (Headlights, indicators etc). The engine will continue to run (as it's on it's own ECU), but the transmission will go into 'limp home' mode - where it will lock itself in 3rd gear. It's designed for just that - to get you home. I had it happen, and then had to get up a hill from standing start from traffic lights...

Hope this helps/gives you somewhere to start! It sounds scary, (and sure freaks you out when you're driving and all the instruments just stop) but BECM issues aren't as bad as they used to be now there are people out there who can repair/clone them! (and getting the BECM done is a LOT cheaper than it used to be too!)

Cheers,
Marty
 

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1995-2002 Range Rover P38A
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Discussion Starter #3
Thanks Marty

That makes sense about the limp home mode for the gearbox. I'll have a go removing the BeCM and checking the surrounding wiring - thanks for the 'how to'.

I have previously changed the heater o-rings so hopefully they haven't gone again, but I'll have a good check around.

Before changing the alternator I was hoping for some sort of safety feature which cut out when detecting high voltage, but I guess that would have been to easy. I'll report back with anything I find.

Thanks again.

P.s. I've updated my profile to show I'm in the UK.
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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4,219 Posts
No worries..

I'm in Swindon, so it that's close to you and you need a hand, then get in touch!

Double check the O-rings/carpet - because I found issues on mine, where it wasn't the O-Rings (I'd bought new ones to discover that they'd already been changed) but a chip in the plastic at the heater core itself... swapped it for an Audi heater core (Pioneered by leftlantruckin and sersan) and no more o-rings for me :)

Callrova is the UK place to go for BECM repairs/service... I've never used them (or had to... yet... touch wood) but that's where I've seen recommended a lot for UK based BECM work..

It might be that the original alternator is OK, but the voltage regulator in it is buggered - hence the over supply of voltage... I'm not sure if the regulators are replaceable - possibly if the alternator is sent away to a company that refurbishes them..

Good luck :)

Marty
 

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1995-2002 Range Rover P38A
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Discussion Starter #6
desetdude, if I read your post right then if I get a donor BeCM then I can swap the power board out without any sync issue's? That'd be good provided it was the power board at fault, but from what I read on the 'net then it is unusual for the input board to be at fault.

My BeCM is AMR5824 but I can only find different AMR numbers on eBay - are these likely to be incompatable, even though they are from similar model years?

As it is, I've removed the BeCM and opened it up but everything looks fine, with no visible burn marks etc. The wiring around the BeCM looks fine and the carpet is still dry.

Thanks
 

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In my case the AMR numbers also didn't match , I just stuck with the H for highline. I'm no Becm expert but from what I know and have seen, the power boards are the same, its the logic boards that are different, and were in my case, but I am guessing they are all wired to work with one standard power board. Yours is probably not as knackered as my buddies as his Range was totally dead.

Seems like your logic board isn't screwed since the car starts and drives, probably one or two relays have conked out on the logic board. Its always worth a try to swap boards, I'm thinking it should work, If it doesn't you still have a Becm that you can send to scotty or someone to have a go at it i.e you won't know until you try and basically you have nothing to loose.

Usually if a logic board goes wonky, it looses sync, starts acting the fool like flashing the headlights, honk and all sorts of other electrical tom foolery. Lemme tell you this though, almost everyone told me, it couldn't be done, its not that simple, the Becm is some monster from another planet and the moment you look at it wrong it will kill you and then hunt down every member of your family and kill them too. Turns out it wasn't half as complicated or scary, infact one of the most easiest DIYs I've done on a P38.

More techincally minded and skilled people than me on other forums have managed to trace down a bad relay or circuit on the Logic board, ordered the same part online and soldered it back in and got it to work.
 

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1995-2002 Range Rover P38A
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Discussion Starter #8
Well, I got a replacement BeCM which came from a 'driven in' P38 and swapped my original Logic Board into the donor BeCM and fitted this, but now I have nothing at all. I tried entering my EKA, and also various ways to sync the remote but still nothing (during previous battery disconnections I have never had to do any EKA/sync as it's just worked). I also no longer get the gearbox fault and fuse blown errors when turning the ignition off.

The weather outside is too wild just now to remove the BeCM to reinstall the original again to check if I can start the car again, but I'll try this tomorrow.
 

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1995-2002 Range Rover P38A
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Discussion Starter #9
Today I got the key sync'd and the engine fired up with the 'new' BeCM power board, but all other symptoms are the same as original. I swapped everything back to original and the engine still runs, but the other problems still persist.

I've checked/cleaned/greased the earth connections at BeCM, under fusebox, chassis mount between fusebox engine, side of waterpump and my earth readings are at 'lead resistance' with a fluke 75. I get 14.01V at the BeCM which is the same as at the alternator and battery when the engine is running (the battery had gone low with all the start/stops and sitting waiting for the donor BeCM, so is now on charge).

I only have drivers side/right lights (side, dip,full and fog - both front and rear). The interior fan runs but as soon as I press the brake pedal, or even turn on the interior lights then the fan slows to a stop. I have full remote lock/unlock. The passenger side windows and sunroof operate, but nothing on the drivers side.

The one point I have noted requires further investigation is the connector "C105" which has no volts at all, and according to this page - http://www.rangerovers.net/repairdetails/becm/index.html then it supplies 12V via the 60A Maxi Fuse 1. I have checked this fuse and it's ok.
In Rave, this 60A Maxi Fuse 1 provides power to BeCM fuse 1, 2, 3 & 4 of which fuse 1 is amongst other things the instrument cluster. Fuse 3 & 4 is to do with the gearbox which makes sense as it is in limp mode.

Can anybody help with any pointers of why the 60A Maxi Fuse is ok but I have no voltage at connector "C105" at the BeCM?

Thanks
 

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If you have 12v (battery voltage) at the 60A fuse and none at C105, that's fairly conclusive somewhere, obviously, is a break/crack. Do you have the same voltage on the underside of the engine bay fusebox i.e the beginning of that same cable that ends up at C105
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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The next common place to look from me would be the fuse box... as they have the reputation or getting cracks/burnt tracks on/in the PCB.

Have you removed the fuse box from the vehicle and inspected it yet?

Have a squizz at this page... it shows you how to dismantle the fuse box... you probably don't need to fully split the PCB's, unless there's a major fault you find and need to fix - but looking at them should give you some idea if any electrical craziness has been going on in there!

http://www.rangerovers.net/repairdetails/electrical/fusebox.html

Sucks about the BECM though - at least you have a spare power board now, in case one of the relays/MOSFET's decides to give up..

Hope this helps...

Marty
 

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1995-2002 Range Rover P38A
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Discussion Starter #12
When I last posted I had only just read the 'Demystifying the BeCM' page again and realised I should have the 12V on C105, but was unable to go back to the car and check it through.
Tomorrow I'll test under the fusebox on C169 which is the other end of C105 and hopefully this should tell more. The fusebox is in pretty good order other than I've noticed the fuel pump relay is slightly brown, but at the moment that isn't bothering me too much as the engine starts/runs fine - I'll sort that once I get the car back on the road. Of course there may be other issue's not so visible.
From Rave I'm guessing the engine fusebox 12V in is from that heavy red wire and will go straight to Maxi Fuse 1, then out onto C169? I'm a bit unsure as in Rave there is the ignition relay R15 which needs to be energised to put power onto the Y1-3 line, but the Maxi Fuse 1 takes it's power from Y1-1 and/or Y1-3(?). I'm thinking this R15 is likely to be ok as it also provides power to several engine running components, including ignition coils via C525.
I'm not familiar with Land Rover or any vehicle schematics at all so this isn't too clear for me, but having something else to work through is giving me hope...
 

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Discussion Starter #13
Marty, you posted as I was still typing so my post may appear to be ignoring your advice, but that's good info. I'll have a real good look at the fusebox tomorrow.

As you write, the spare BeCM can sit waiting for future problems...

Thanks.
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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Ahh, the good old writing at the same time trick!

Hope you get to the bottom of it soon!

Cheers,
Marty
 

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1995-2002 Range Rover P38A
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Discussion Starter #15
Ok, fusebox was stripped down so I thought I'd repair that fuel pump relay terminal while I was there - not a nice job! The repair was easy but re-doing all those links is a PITA. Other than that the pcb was in good order and I'd checked continuity and IR between tracks and all appeared good, so I reinstalled it. Still low voltage at terminal C105 at the BeCM, so I thought I'd check for voltage underneath the fusebox but as I tipped it over I shorted the terminal to earth and popped the 60A fuse. I borrowed one from an ajacent Maxi Fuse slot and found good voltage at the outgoing fusebox terminal but still had low/spurious voltage at C105. This now had to be either a wire break or insulation breakdown dragging the volts down.
I started pulling off trim along the floor at the side of the drivers seat and when I unravelled all the cables I saw a tell-tale green copper oxidisation around a cable bundle. The wire insulation had broke through and probably a mixture of damp and shorting against a panel joint (hence a sharper edge) had caused the break. I quick temporary joint was made and full battery voltage was now at the C105, and when the ignition was tuned on I had my dash message display back, but as I don't have a spare fuse I couldn't start the car to test everything fully.

When I turned on the headlights I still only had right hand/drivers side lights on both the front and rear, so I need to check if the higher voltage when the alternator regulator packed up, has possibly caused the bulbs to fair (but only on one side???). It's dark outside again so at least I have a positive mind for going forward with repairs/further checks tomorrow.

I nearly feel confident my P38 isn't going to get broke up now....
 

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Discussion Starter #16
My Range Rover is back on the road again!

I fitted a new 60A Maxi Fuse and then the car started up with the usual windows alarms - but then an Airbag Fault message. I reset the windows so now the only message is the airbag. I have done a search and the general picture I get is that I just need a Testbook reset. Thankfully the car had it's MOT just days before this issue, so while I'll try to sort this soon at least I'm not forced off the road with the MOT's now failing for airbag warnings.

This is an example of how we (I) went straight for the complicated stuff when the fix cost less than £2 in the end.

Thanks once again for those who wrote with idea's/help.
 
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