P38A 98 2.5 DSE With electrical issues

spadgr said:

The Faultmate is Vin locked, as regards sorting out the original Becm, i think i would have to send it to the UK and that means it would be off the road for quite a while. There are a couple of electronics places over here, but given all the headaches i have read about, i'm not sure i would want somebody who doesn't know what they're doing have a look as i may end up just digging a deeper hole.
If i swap over the logic boards, would i not be in the same boat? as i would think the logic board would probably control the immobiliser. I have read on the internet about soldering in a plug that gives direct access to the control microprocessor and allows it to be unlocked (Sm035), does anybody have the pinouts for the plug so that i can make one myself? Also is my MSV Extreme likely to have the appropriate software installed to allow me to overwrite the settings? Anybody on here done it?

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I meant take the logic board with the valid immobiliser code in it out of the (presumed) broken BECM and put it in the BECM with the working power board. All should work as before then. You can reset the immobiliser code with Nanocom or Faultmate easily enough. The BECM has a load of little bolts on top. Undo them and there are 2 boards inside. Cannot remember which is which now but 1 is the logic board. Nothing special required to get it out. You can read the chip with the data an using an appropriate socket (EEPROM?) reader and scraping the protective lacquer off the pins and pushing the socket against the pins to make contact.

BECMs do fail but it is rare. Usually they just go out of sync with the engine ECU. Marty can repair some or Rick-The-Pick is the undisputed BECM God.

I've had BECMs come from NZ, US, Canada before to reprogram them - I have the MSV2 with the BECM CPU module so can reprogram logic boards.

You won't be able to read the CPU without this, and as others have said, if the Faultmate is VIN locked, then you won't be able to talk to the replacement logic board anyway. You need the Multi-Vehicle licence and the SM035 module to be able to do what you need to do. Unless the BECM has already been unlocked and had the programming lock turned off, even if you were able to talk to the replacement logic board, you wouldn't be able to program it without the CPU software module.

If you are pretty sure that the power board is OK, then you could just send me the pair of logic boards, mark them as which is original and which is the replacement, and I can clone all of your original vehicle settings onto the new logic board. Since this will also transfer things like the fob code, and VIN, your remote fob will work with it, and also the Faultmate will then connect with the replacement board, as the VIN will match what it is locked to. Just sending the logic boards cuts down a LOT on shipping size/weight, and therefore cost. Have a look on my website p38webshop.co.uk under the BECM programming/cloning section, and it will tell you what I offer. Also, I still have an NZ bank account, so can accept NZD, which might save on currency conversion fees

Feel free to drop me a message or email if you want a quote, or any more information - but from what I have read, you won't be able to get it to connect to your faultmate without either re-licencing it, or getting the board cloned.

Also it's worth swapping the original logic board into the other BECM housing (even if there is a high line/low line mismatch - all the core functions will work, but things like Sunroof/Front fog lights won't) as a test to make sure it is the logic board which is faulty before sending it off anyway. You might find you can clean the corrosion on the logic board with some contact cleaner (I use an old toothbrush to scrub around pins etc) and with it then in a replacement case with another power board it might work. If you still get the same issues with another power board, then there is obviously an internal issue on the logic board, and it will need cloning to the spare one you have. Luckily the knowledge/tools for these things are more widely out there these days - My first P38 in NZ had BECM issues from a previously improper fitted fuse box which shorted out one of the main supplies to the BECM and damaged it internally... replacement cost for all the work done and the unit was about $3.5K at the time... this was about 14 years ago though! It's definitely nowhere near that expensive these days!!!

Hi Marty,
Im guessing that the logic board is the board on the bottom of the 2 in the Becm, the one without all the bits and pieces on?
I'm not sure of the condition of the donor Becm in any way, I just decided to fit it and see what happened and as I say, when we turned it on after fitting, everything seemed ok, the petrol flap didn't ping open or horn sound etc it just wouldn't start. Last night I refitted the old Becm and the wagon starts, but still the same issues, ie petrol flap opening horn intermittent beep etc. Surely it can only be the Becm.
On another note, I tried to follow the link to your webshop, but the page wouldn't open. I will have a hunt and see if I can access another way.

Ooops, I forgot to put the link in an actual 'link' www.p38webshop.co.uk <-- try that one

Yes, the issue is almost certainly in the BECM somewhere -but if it start/runs, then I at least some of the logic board is working.

What else does it do other then the horn/petrol flap randomly activating? The inputs for both of these are on the same connector on the logic board (the yellow one under the fuse box), and whilst the outputs to the fuel flap and horns are on different connectors, they are both on the front edge of the BECM closest to the footwell and potential moisture.

My next step before deciding if anything needs to be sent anywhere would be to remove your original logic board, and swap it into the replacement BECM box (so you are using the other power board) and then see if it still does the same thing. If it does, the fault is on the logic board (whilst it's out, look carefully around the yellow connector at the pins for signs of corrosion, even mildly on the surface that could cause interference between different pins and clean any with isopropyl alcohol/contact cleaner). If it doesn't do the thing with the horn or the fuel flap, then the fault is on your original power board.

Once we know which board the fault is on, will determine the best course of action. If you're able to send me a few decent resolution photo of the logic board, especially around the yellow connector, I am happy to look over it and see if there is anything obvious there that you might be able to repair, or get repaired locally

I swapped the power board from the donor BECM to my housing with the original logic board in and there was no change, everything was still up the chute, but at least it allowed me to drive it home. Tomorrow i will put my original power board with the logic board from the donor Becm and fit back to the vehicle and see what happens.

martyuk said:

What else does it do other then the horn/petrol flap randomly activating?

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When fitted with the "faulty logic board", the fuel flap pings open randomly, the horns (all three of them) toot randomly, just real short toots, both of these things happen with the key out. When i initially reconnect the battery after refitting the Becm, there is a decent spark and so i guess there is something drawing a fair amount of current. The central locking doesn't work anymore. When the ignition is turned on, the headlights illuminate and the headlamp switch has no effect whatsoever, the headlamp washers squirt and headlamp wipers go for a brief period and then stop and the windscreen wipers no longer self park. It sounds to me as though the starter solenoid is engaging for a split second sporadically also (which was a bit nerve racking when driving it home from work) although this seems to become less after the battery has been reconnected for 10 or 15 minutes. There may be other things that i haven't noticed, but when driving it home it all seemed OK. Not sure if this may also be relevant, but the stereo stopped working a few months ago. The sound just went, but when you turned it on, it would light up very dimly and you could here static very faintly.

Once i am certain of the cause, i will send the necessary bits over to "martyuk" for repair.

I wonder if it is the BECM. Electrics isn't my thing but it seems like a short somewhere. Have you checked for parasitic drain? Anyone put any screws in anywhere recently and might have clipped a loom?

We had a P38 in from another garage here in the Algarve kept blowing No 1 fuse on the BCEM original garage and owner sent ECU, becm etc to callrova twice and bought new fuse box... turns out it was trapped wire to window switch pack traced with help from Martyuk

@RangeRoller dt original garage had the car in February Barry got it in May owner and English Mechanic messed us around for months with wrong bits they bought as they knew best.. a single reply from Marty took us 20mins to solve the next day...

@Shippers So it runs okay now?? Thought that one was gonna be long term project....all done in few weeks

RangeRoller dt said:

@Shippers So it runs okay now?? Thought that one was gonna be long term project....all done in few weeks

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No No the above was a customers car he's got it back now... going to start a new thread this week on our other 2 P38s... will be interesting to hear peeps thoughts...