Wonky operating headlights. Bizzare and strange.

[davidsonsm]

I have to confess to having the illegal bi-xenon kit fitted from hids4u out of the UK. They've worked fine and have been brilliant. And I've been very conscious of lighting up the rear view mirror and the bald head of the cars in front - but quite simply, haven't been as far as I'm aware.

However, I now have a situation where the left dipped beam isn't working and the right full beam isn't either. The left full beam does work.
I've checked voltages the lights and I'm not getting any. I've plugged in my old halogen h4 bulb and that doesn't work either.

Does all of this point to an issue with the becm?

I'll check the voltage output from the becm as well.

P38's are like squeezing a baloon.

[benji]

Or wiring. Obviously a dmm wont read the voltage at a hid bulb as its to high.

Yes, if you haven't got voltage at the becm plug then you've got problems. I wonder if the ballast resistors for the hid have a high inrush current; not sure if the relays in the becm would like that.

Do you get any messages on the dash?

Sent from my GT-I9305T using AULRO mobile app

[davidsonsm]

Yeah the dash is telling me what's wrong. So the becm is picking up the problem. Had to be becm related wouldn't you say. Originally it was the dipped beam on the right that wasn't working, but that righted itself at the expense of the left.

[Hoges]

Yeah the dash is telling me what's wrong. So the becm is picking up the problem. Had to be becm related wouldn't you say. Originally it was the dipped beam on the right that wasn't working, but that righted itself at the expense of the left.

sounds political:eek:;)

[johnyrover]

P38's are like squeezing a baloon.[/QUOTE]

[ringo]

Sounds like the BeMC thinks the bulb is burned out. Take a look at this link, in the middle of the page is a modified schematic that should eliminate this type of trouble. I hope it helps.
Range Rover P38 Maintenance repair improvements and tips learned by experience by ownership. (http://www.stockholmviews.com/p38/)

[davidsonsm]

I've narrowed my headlight problem down to the BeCM. I'll take it out and look for any obvious issues, and give it a good clean. Two questions I'd like to solicite help with:


if I can't cure the problem using my usual hamfisted approach, is there somebody in Australia (preferably Melbourne) that can work on the PCB's?
if I do spot a faulty relay or power transistor (MOSFET), can you still buy them and where?
Mine has just hit that 15 year old stage. It seems like everything I've read about is coming true. I used to read with interest the misfortune of others. Now its Nora's turn.


Best regards - Sean.

[wayneg]

Out of curiosity were you getting a bulb out warning whilst the Hids were still working correctly. Did you have a Complete plug and play kit or one where you had to add a separate loom
If you can get access to diagnostics you can test each lamp individually, not sure what that would prove if they did all light up but would at least show the wires were all intact.

[davidsonsm]

Wayne, its definately the becm. I've traced voltages all the way thru. I get the same result if I sub the H4 halogens back in. When the HIDs were working there was no error message. The HIDs came complete with a control box (ballast? ) and wiring that was compatible to just "plug and play". But as was suggested earlier, maybe the inrush current had led to the demise of a power transistor. Somebody out there must have a drawer full of them.

Anybody tried the LED headlights?

I might try and get a spare BECM for spare parts. Just need the part number for mine.

[Hoges]

Wayne, its definately the becm. I've traced voltages all the way thru. I get the same result if I sub the H4 halogens back in. When the HIDs were working there was no error message. The HIDs came complete with a control box (ballast? ) and wiring that was compatible to just "plug and play". But as was suggested earlier, maybe the inrush current had led to the demise of a power transistor. Somebody out there must have a drawer full of them.

Anybody tried the LED headlights?

I might try and get a spare BECM for spare parts. Just need the part number for mine.

The electronic industry identification part numbers for the BECM power transistors are BUK202-50Y and BUK203-50Y.

It's been a while since I got enthused over these... they are critical to the BECM obviously:eek: and in a similar category to the crankshaft position sensor as regards being a "show stopper" if they fail. Thankfully, provided there's no undue current demands made on the BECM, they are highly reliable.

The not-so-good news is that these particular power transistors appear to be no longer manufactured and certainly not available for purchase in small numbers. However, other posts in rr.net and IIRC on here, indicate that they have been superseded and that the updated MOSFETs can be substituted.

Rupert Prior on this forum is most knowledgeable on these matters (i.e. the secret life of BECMs!) and may be able to assist.

I haven't had the need or desire to examine my BECM intently. If the BECM electronic components have been assembled using so-called "surface mount technology" then replacement of the MOSFETs will require a delicate touch indeed with a soldering iron and lots of know-how...

[benji]

A few years ago now I was in jaycar, and they were able to get the superceded ones in bus of three. They were from the US, and not that expensive.

[davidsonsm]

Cheers benji. Yeah I'll definately give jaycar a try once I've removed the becm. I'll give digikey.com a try also once I've found the offending culprit.

Seems odd that it's the left hand dipped main beam, but right hand full beam. They enter the becm through different connectors. But must share a common failure point? Strange.

[TheTree]

Hi,

There is a massive thread on those MOSFET's here

BECM Mosfets (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/5351-becm-mosfets.html)

I just found a site which says they have stock of both and they ship to OZ !

BUK203-50Y and BUK202-50Y

Just need to make sure the package is the same, ie. SMD style

LittleDiode - Electronic Components Supplier (http://www.littlediode.com)

Regards
Steve

[rc42]

I had the dual H4 HID bulbs for a while and also a set of H7 HID bulbs in the aux driving lights but I recently took them all out.

The moving magnet on the H4 bulbs would occasionally stick between hi and lo positions which meant glare for oncoming drivers an be having to stop and get out to 'hit' the lights to get the magnet to move fully.

Also, I had enough of losing all of the dash lights for a second or so when switching to main beam, I didn't think that this was good for the BECM, the slow start of the HID bulbs also makes them less than ideal.

These days I have a dual LED H4 bulb (two single Cree LEDs) that puts out more light than standard bulbs and have a really good cutoff pattern and I've put standard filament bulbs back into the aux lights, the BECM is now perfectly happy with all of the bulbs. I have also put a 40" LED light bar with 80 3W LEDs across the front for those extra dark nights, amazing light spread but not great for distance but it was the cheapest I could find at about $480.

[davidsonsm]

Yes - reckon I'll be removing the HID's. Go back to Halogen's. Although the LED headlight bulbs have caught my eye. Good to hear positive results with them.

[davidsonsm]

I've acquired a couple spare MosFets of each type - can't hurt to have them as spares. I'll also try and get a spare BeCM for parts.

I'll have a delve next weekend and see if there's anything obviously wrong.

As stated, I reckon the HID's have caused this issue. They'll be coming out.

[Keithy P38]

The LED's you speak of, are they the 25w twin Cree LED jobbies that I'm seeing over eBay? About 1800 lumens?

Have you a pic?

Were they simply plug n play or is there more involved?

Cheers
Keithy

[marty_nz]

The BECM MOSFETS are just soldered in - but are soldered top and bottom on the boards. I've read the easiest way to get them out after unclipping the heatsink is to chop the leads, and then you can de-solder each leg individually.

The replacement part numbers are:
BTS410-E2 (which replaces the BUK203-50Y) and
BTS432-E2 (which replaces the BUK202-50Y)

The headlights are run off the higher current BUK202-50Y/BTS432 MOSFETs

I think you can still purchase the BTS410 and BTS432 varients. I also have a diagram somewhere I made of all the BECM MOSFETs and what they drive...

Hope this helps,
Marty

[marty_nz]

Just as an aside - you DON'T want the SMD MOSFETS - you want ones in a TO-220 (5 pin) configuration. Sometimes also listed as SOT263

http://www.aulro.com/afvb/attachment.php?attachmentid=71907&stc=1&d=1390872873

I would also be interested in seeing what the LED headlights look like - I've been considering getting a set of H3 ones for my fog lights as a test, before giving the dual chip ones a go in the H4 form for the low/high beam...

[davidsonsm]

Marty - if you could help me identify which part of the board to inspect first with regards to the headlights - I'd be most chuffed.

Thanks in anticipation. Top bloke. best Regards - Sean.




The BECM MOSFETS are just soldered in - but are soldered top and bottom on the boards. I've read the easiest way to get them out after unclipping the heatsink is to chop the leads, and then you can de-solder each leg individually.

The replacement part numbers are:
BTS410-E2 (which replaces the BUK203-50Y) and
BTS432-E2 (which replaces the BUK202-50Y)

The headlights are run off the higher current BUK202-50Y/BTS432 MOSFETs

I think you can still purchase the BTS410 and BTS432 varients. I also have a diagram somewhere I made of all the BECM MOSFETs and what they drive...

Hope this helps,
Marty

[davidsonsm]

This is what I've ordered - 2 of the BUK202-50Y's and 2 of the 203's.

There's also a CW suffix version - not sure what that is. Have I done right?

When you search on the later part number (BTS432E) it comes up with a Siemens product.


https://www.littlediode.com/components/search.php'mode=search&simple_search=Y&posted_data%5Bby_title%5D=Y&posted_data%5Bby_shortdescr%5D=Y&posted_data%5Bby_fulldescr%5D=Y&posted_data%5Bby_sku%5D=Y&posted_data%5Bincluding%5D=all&substring=buk202-50y&search_redirect=Y

[marty_nz]

Here is the Layout I've traced the MOSFETS to for various outputs.

There are still a few that I haven't traced the outputs to, as I was mainly interested in the ones for all the lights.

I've listed these with the BTS part numbers, as that what's on all 3 of the BECM's I have kicking about here...

Orientation is looking from the 'Bottom' of the BECM - with the Slate (Grey) and Yellow plugs facing towards you (would be the front of BECM when in the vehicle) and the Fuse Box to your left.
Hope this helps...

Marty

[rc42]

The LED's you speak of, are they the 25w twin Cree LED jobbies that I'm seeing over eBay? About 1800 lumens?

Have you a pic?

Were they simply plug n play or is there more involved?

Cheers
Keithy


Yes, those are the ones, mine were $112 back in November but I think they can be found even cheaper now.

Light output is 'softer' with a very even pattern and good cut-off, although not as bright they have the 5000K colour temperature of HIDs but with instant startup and the high beam adds the second LED for the full 50W output per side.

Simple plug and play to fit and no BECM errors, they do have a cooling fan on the back which doesn't work well with the rubber dust protector that normally goes on the back of the headlamp assembly so that may be an issue if you play in the mud a lot.


http://www.ebay.com.au/itm/Universal-Car-Auto-H4-1800LM-50W-Cree-LED-HeadLight-Head-lamp-H-L-Beam-White-/121140673638?pt=AU_Car_Parts_Accessories&hash=item1c348bfc66

[davidsonsm]

[That's awesome. First documentation of its type that I've seen. Many thanks for sharing.

I now understand why the LHS outboard dipped beam and the RHS outboard main beam can fail independently - becaue they are independently controlled.


QUOTE=marty_nz;2075418]Here is the Layout I've traced the MOSFETS to for various outputs.

There are still a few that I haven't traced the outputs to, as I was mainly interested in the ones for all the lights.

I've listed these with the BTS part numbers, as that what's on all 3 of the BECM's I have kicking about here...

Orientation is looking from the 'Bottom' of the BECM - with the Slate (Grey) and Yellow plugs facing towards you (would be the front of BECM when in the vehicle) and the Fuse Box to your left.
Hope this helps...

Marty[/QUOTE]

[marty_nz]

Yeah, All of the lamps are controlled by their own MOSFET. The MOSFETS have built in load sensing - which then gets passed on to the logic board via another chip (think it digitises the analogue signal from the MOSFET) and that is in turn how the BECM generates it's BULB FAILURE messages.

@RC42 - I gather from what you've said, that the LED units aren't as bright as the HID's - which is understandable, but how do they compare to the standard Halogen version? are they brighter than those?

[davidsonsm]

Swapped out the upper power board on my BeCM today. Highline for highline although the part numbers printed on the fuse block housing were different.

All seems ok. But I'm too nervous to turn on my headlights in case I blow another mosfet. Ill solder new mosfets in to my original board and keep it as a spare.

Ill get some LED headlights instead of the HIDs to help prevent a repeat.

[davidsonsm]

The other benefit of taking your front seat out, is it makes you rich. $1.55 in coins. Plus a beer bottle top, a chewing gum pellet and lots of otjer detritus - crisps mainly.

Might see what the passenger has been eating this last 15 years.

[davidsonsm]

So I put some new LED headlights in tbe car today after swapping out the BeCM power board a couple of weeks back.

I still have the same headlight problem. It would be too much of a coincidence if the spare power board had the exact same blown mosfets.

Ill double check what voltage is coming out the BeCM.

But could this point to an earthing issue?

Also my right front indicators have also stopped working. This is getting rather frustrating. I checked the green and white wire on connector C113 - position 4. There doesn't seem to be any power coming out the BeCM.

Could a problem on the logic board cause this issue if the mosfets were good?

[TheTree]

HI

This could be an earthing issue or a logic board fault.

Have you tried measuring the voltage across the bulb connectors?

Steve

[davidsonsm]

I get 12volts plus from the BeCM when checking the LH dipped beam. Ill check what I get at the headlight.

The dash tells me the bulb is out, indicating to me the logic works.

[Scouse]

Bulb warnings are displayed if the current draw doesn't match what is expected. Factory globes are 55/60w so anything less than that will trigger the warnings.

[TheTree]

Hi

Do you get 12V at the connector with a load connected?

I am thinking you may have some high resistance connections somewhere in the circuit so that you get 12V with no load, but it drops badly under load.

Steve

[davidsonsm]

I'll check it out. The problem is that to gain access to the light fitting, I have to remove the air box - because my EAS manual inflate valves/tank pressure gauge/nitto outlet gubbins block access.

Thanks for the advice. Not much good when it comes to the mystique of electricity. I'm getting 12.65V at the pin on the BeCM. I'll see what it is at the headlight.

I'll also check the earth continuity.

[wayneg]

So I put some new LED headlights in tbe car today after swapping out the BeCM power board a couple of weeks back.

I still have the same headlight problem. It would be too much of a coincidence if the spare power board had the exact same blown mosfets.

Ill double check what voltage is coming out the BeCM.

But could this point to an earthing issue?

Also my right front indicators have also stopped working. This is getting rather frustrating. I checked the green and white wire on connector C113 - position 4. There doesn't seem to be any power coming out the BeCM.

Could a problem on the logic board cause this issue if the mosfets were good?

I recently put some of the Cob Led headlights in mine, got what they claimed are 2nd generation, higher output. No errors and very good lighting, strangely not as white as the Hids but much whiter and brighter than the Halogens. Plug and play with Zero issues. Looking at the emitters they dont look much but rest assured they are unbelievably bright
http://www.ebay.com/itm/1-pair-H4-60W-Hi-Lo-Beam-2nd-Generation-COB-LED-Car-Headlight-Fog-lamp-6000K-GGG-/261366670776?pt=Motors_Car_Truck_Parts_Accessories&hash=item3cdaaae5b8&vxp=mtr

[TheTree]

I recently put some of the Cob Led headlights in mine, got what they claimed are 2nd generation, higher output. No errors and very good lighting, strangely not as white as the Hids but much whiter and brighter than the Halogens. Plug and play with Zero issues. Looking at the emitters they dont look much but rest assured they are unbelievably bright
1 Pair H4 60W Hi Lo Beam 2nd Generation COB LED Car Headlight Fog Lamp 6000K GGG | eBay (http://www.ebay.com/itm/1-pair-H4-60W-Hi-Lo-Beam-2nd-Generation-COB-LED-Car-Headlight-Fog-lamp-6000K-GGG-/261366670776?pt=Motors_Car_Truck_Parts_Accessories&hash=item3cdaaae5b8&vxp=mtr)

Hi

I note these have the heat sinks at the rear, does this mean that the LR waterproof covers no longer fit?

Steve

[davidsonsm]

I had to cut away the inner rubber so the cooling fan on the led's could protrude through.