BogMonster Posted February 3, 2009 Share Posted February 3, 2009 Got a major problem with a P38 diesel auto at work wondered if anybody could help please? I don't know a damn thing about them (apart from I wouldn't touch one with a barge pole) as there are only a couple of them in the country and they are grey import second hand ones, they were never sold here new. It was driven in to the workshop for some work on something else and something has gone pop - apparently coincidentally - and now it doesn't go. I hate it when that happens Basically the vehicle is totally dead the engine will crank over on the key but no life at all - it isn't even trying to fire. There seems to be power and earth to the BMW engine ECU according to the meter and the connector pin layout in my RAVE diagrams, but the diagnostic won't talk to either the engine or the autobox ECU just gives comms errors. Neither the glowplug light nor the Check Engine light come on when you switch on the ignition. The lights on the gearbox console show gear selection as does the instrument pack, and the diagnostic will communicate with the BECM with no problems. Any ideas please? If the ECU is dead, is there any way to confirm this? - I hate to think what one would cost and can't afford to order one "just in case" as it is no earthly use to anything else round here and will be a few weeks getting here anyway. Ta Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted February 3, 2009 Share Posted February 3, 2009 Stick disc 18 in your T4 to talk to the autobox ECU - its about the only one that will talk to it - and then only if the battery is well up.Go into EDC and sub systems tests or vehicle maintenance and do a security relearn on the engine ecu - same as EDC 300TDI Disco.After that it will go.(I hope ! ) Often dying eng compartment fuseboxes or rotting wiring/connectors between the EDC ecu and the BECM are the culprits for losing the coded link.Here in the UK stray RF activity causes the flat battery symptoms - AND lose the code too. Good luck ! Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 3, 2009 Author Share Posted February 3, 2009 Thanks, will try the trick with the disc and autobox ECU but as far as the engine one goes - totally dead no response at all, when it prompts you to connect the diagnostic cables it then spits a comms error every time and you can't get further into it. Any other ideas on this? Could the engine ecu think it is "locked/alarmed" hence refusing to communicate with the T4? Quote Link to comment Share on other sites More sharing options...
Escape Posted February 4, 2009 Share Posted February 4, 2009 Even in a locked/alarmed state, the ECU should still communicate. Never had any trouble accessing the ECU with a Rovacom, but have heard others complain about similar problems with other readers. My first guess would also be to check the fuses, relays and wiring, as Ally suggested. Best of luck! Filip Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted February 4, 2009 Share Posted February 4, 2009 Thats a bit odd,any of the discs should work on the EDC ecu,its just the autobox one thats a pain.Check for resistance on the dignostic wire from the plug to the ecu,there is a about a 6 way splice on the pink/red,(From distant memory on the colours) which is below the heater pipes.Seen the leaking o rings rot the splice and play allsorts of tricks.Worst case I suppose it could be a dead ecu. Quote Link to comment Share on other sites More sharing options...
SteveG Posted February 4, 2009 Share Posted February 4, 2009 Stephen, contact Rick at Call Rova and mention RangerRovers.net and LR4x4 when you speak/e-mail him. I'm sure he'll be able to help with some further diagnostics or worst case he can repair P38 ecu's. Normally he can send one in exchange to help cut down on your long shipping times. He has a very good reputation. Cheers Steve Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 6, 2009 Author Share Posted February 6, 2009 OK some more on this.... The splice under the heater matrix was a bit messy (it was being leaked on as suggested) - duly repaired. Definitely have 12 volts to the required pins in the ECU & a good ground. Continuity seems to be OK on the two wires between the diagnostic plug and the ECU pins but still no go - won't communicate with the Testbook. T4 diagnostic is carp and crashes every time halfway through the "diagnose comms failure" routine so that isn't much help Looking at what else does what, the glow plug relay doesn't operate when ignition is switched on, nor does the fuel pump relay, but both appear to be supplied from the ECU according to the diagrams. Triggering the fuel pump relay manually (taking the lid off the relay & pressing the contact shut) that works fine so that isn't the problem. So its got power and earth going in at the appointed time and place, but bugger all coming out... I'm leaning more and more towards a dead ecu as being the cause? Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted February 6, 2009 Share Posted February 6, 2009 Does sound likely,they are normally easy to talk to so having gone that far,(and thinking of your position re LR diagnostics.) I think a slave ECU to code up is the next step.I have a similar car with allsorts of problems that has been sat for nearly a year in my yard,(Local indy - no money, why should I bother ? ) and it wont talk to T4 or run properly.Not touched it for months,tyres are flat,spiders have moved in and I bet its mouldy inside too. I cant remember if there was a spare EDC ECU with it,I'll have a look on Monday when I go back to work.How long does post take to get to you from the UK ? Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 9, 2009 Author Share Posted February 9, 2009 Hi, Thanks for that. Post by airmail takes 7-10 days. I've found one of the other two P38s in the country and have that coming in just to test the T4 and rule out it isn't the diagnostic tomorrow, and see how the diagnostic should work when its working properly, however not able or willing to pull bits out of it being a customers vehicle and one that is actually running...! What I did see when I bumped into him on the weekend is that the check engine light should come on for approx 5 sec when ignition is switched on and this one doesn't so that is probably another nail in the ECU's coffin And I have the bluddy flu Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted February 9, 2009 Share Posted February 9, 2009 Who is not willing - you or the owner ? Its 2 mins to do a security relearn on the donor ECU and then you would have the answer.You could also suggest that the faulty car one day may help in the same way. I know its difficult when subbing over parts from other cars but I think you are far enough down the line for it to be the next sensible step. Flu is a pain,but sometimes an enforced rest is a good idea.( I never see it that way when i've got it tho....) Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 10, 2009 Author Share Posted February 10, 2009 Both really - he wouldn't be keen to do it as he's had enough problems with his one already, and I'm not keen to fart around with one thats actually working at the risk of ending up with two dead ones if "whatever killed the ECU" does the same to the other ECU. How much does a recon ECU cost anyway? I had a Google around but nothing much came up. Quote Link to comment Share on other sites More sharing options...
Escape Posted February 10, 2009 Share Posted February 10, 2009 Both really - he wouldn't be keen to do it as he's had enough problems with his one already, and I'm not keen to fart around with one thats actually working at the risk of ending up with two dead ones if "whatever killed the ECU" does the same to the other ECU.How much does a recon ECU cost anyway? I had a Google around but nothing much came up. If you do decide to swap, I'd do it the other way around: put the one you suspect is faulty in a good car, to make sure the ECU is at fault and not the wiring. Less risk as well. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 10, 2009 Author Share Posted February 10, 2009 Well I've just sounded the owner of the working one out and he doesn't want to do it so that's not an option. It did confirm the diagnostic was OK and the connection between the keyboard and the floor was working fine. £325.00 in the four year old price list for a new ECU which isn't as scary as I thought (the ecu for my Thor V8 is about £1400...) Quote Link to comment Share on other sites More sharing options...
BogMonster Posted February 16, 2009 Author Share Posted February 16, 2009 Ho hum. No new ECU's available according to suppliers, and no date Looks like second hand/recon is the only option... apart from Call Rova above anybody else I should try? Basically whoever is cheapest! Have emailed Callrova anyway. I assume on these engines that you can code any ECU to any vehicles? Just wondered as the other BMW engine I am blighted with (Td4 in the Freelander) you can't do that according to the book and once coded to a vehicle you can't then put it in to any other vehicle ever. Three of the four LR vehicles in the workshop on Friday afternoon had BMW engines in them - German reliability my codpiece!! Quote Link to comment Share on other sites More sharing options...
BogMonster Posted April 9, 2009 Author Share Posted April 9, 2009 New ECU finally located at CWS with the help of Ally V8 and just fitted to the vehicle, I have never been so happy to hear an 11 year old diesel engine clatter into life Ten minutes of muttering darkly at a lack of cooperation from the air suspension was solved by looking under the back end - ah - it now has coil springs fitted Very many thanks to Jon (Ally V8) for his help with the problem and with tracking down a working ECU suitable for the vehicle :i-m_so_happy: :i-m_so_happy: Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted April 10, 2009 Share Posted April 10, 2009 Glad its sorted,always a relief when a job that is hanging on gets sorted.I'm a bit closer to you at the moment,on holiday in western Australia,transport is a 67 SIIA with Holden power. cheers Jon. Quote Link to comment Share on other sites More sharing options...
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