999dai
Junior Member
Hi all, Really hope someone can help
Posts: 9
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Post by 999dai on Jun 25, 2020 14:57:50 GMT
Hi all,
really hope some one can help. I have owned by 2005 2.0 D4D for approx 5 years and not long after getting it the Rav went into limp mode and showed P1251 fault. it only happened occasionally so lived with it for a few years. recently the fault started happening more and more and the rav became quite unreliable, the fault was made worse when towing the caravan. so decided to seek advise. i was told that fuel was the problem so i had fuel filter changed and put cleaner in with the fuel. this seemed to help for a short while but then came back with a vengeance. anyway, to cut a long story short I've changed the turbo, EGR valve, both SCV valves, Turbo boost solenoid and also the little sensor at the top of the vcv valves but I still have the problem. Car seems to drive ok but when getting to approx 2500 rpm the engine splutters and if you keep the gas on it shuts down and EML comes on and revs drop to 1000 rpm. turn ignition off wait a few seconds restart and she goes fine again. spent loads of money so getting a bit desperate as don't want to send her to big scrap yard in the sky. any advise would be great received
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Deleted
Deleted Member
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Post by Deleted on Jun 25, 2020 20:23:48 GMT
I am probably wrong but could it be due to some electronic ECU board fault that requires the ECU unit to be sent away for repair by experts?
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Post by shcm on Jun 25, 2020 21:37:09 GMT
Despite people often pointing the finger at ECUs (possibly because they have problems understanding them), they are amongst the most reliable bits on a vehicle. (Somebody will now point out the RAV auto gearbox, but I suspect that was down to inadequate transient protection on some of the output drivers @ design time). However, it's not beyond the bounds of possibility to get, say, an intermittent VRV driver fault or even an intermittent harness fault for example. The attached may or may not be of some help, assuming it's not just something like the vanes coked up/sticking again.
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Post by sich1 on Jun 25, 2020 21:54:19 GMT
my 4.2 comes up with that fault code when the variable vanes start to stick, and also at around 2300-2500 rpm. i see you changed the turbo amongst other things, but just sharing my findings. a can of bg224 and a goos run cures my problem for a few months.
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999dai
Junior Member
Hi all, Really hope someone can help
Posts: 9
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Post by 999dai on Jun 26, 2020 15:03:26 GMT
Thanks for the responses, the finger seems to point at turbo issues and lots of googling also points me in that direction which is why I took the plunge and replaced it, the fault was still there straight after the replacement. the attached pdf seems to point at the ECU as ive changed all the other parts on the list. Maybe time to give up and cut my losses.
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Post by sich1 on Jun 26, 2020 15:38:19 GMT
20 quid for a tin of bg244, gotta be worth a try before you ditch the rav ?
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Post by firemac on Jun 26, 2020 15:39:03 GMT
Thanks for the responses, the finger seems to point at turbo issues and lots of googling also points me in that direction which is why I took the plunge and replaced it, the fault was still there straight after the replacement. the attached pdf seems to point at the ECU as ive changed all the other parts on the list. Maybe time to give up and cut my losses. You can send the ECU to ECUtesting in Derby and they'll check it out. If it is faulty there is a charge to repair it but if not, they'll tell you and only charge for handling and return postage. In any event you will get a definitive answer as to whether the ECU is at fault or not. 👍
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Post by three5 on Jun 26, 2020 15:41:49 GMT
Thanks for the responses, the finger seems to point at turbo issues and lots of googling also points me in that direction which is why I took the plunge and replaced it, the fault was still there straight after the replacement. the attached pdf seems to point at the ECU as ive changed all the other parts on the list. Maybe time to give up and cut my losses. Where are you based?
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Post by shcm on Jun 26, 2020 15:50:17 GMT
Here we go again, prematurely pointing the finger at an ECU, when other things haven't been eliminated. Electrically, for automotive, the weaker links in the chain, before condemning the ECU, are always the connector and the wiring harness. IMHO, a quick, simple, wiring harness impedance (resistance) check should be done and if possible the VRV drive waveform should also be checked. Anything lower than approx "battery voltage" at pin 1 of the VRV at any time (probably needs an oscilloscope, although a DMM may display an average) would indicate a harness/connector problem. With oscilloscope at pin 2 of the VRV, if the low part of the PWM (pulse width modulated) waveform there doesn't pull close to ground and it does pull to ground with the oscilloscope at the ECU pin, that would also indicate a harness/connector problem. It may indicate insufficient drive current for the VRV (not due to the ECU, but due to an ageing harness or connector or corroded/dirty connector). ....still more likely to be a soot/mechanical problem.
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Post by firemac on Jun 26, 2020 16:29:29 GMT
Here we go again, prematurely pointing the finger at an ECU, when other things haven't been eliminated. Electrically, for automotive, the weaker links in the chain, before condemning the ECU, are always the connector and the wiring harness. IMHO, a quick, simple, wiring harness impedance (resistance) check should be done and if possible the VRV drive waveform should also be checked. Anything lower than approx "battery voltage" at pin 1 of the VRV at any time (probably needs an oscilloscope, although a DMM may display an average) would indicate a harness/connector problem. With oscilloscope at pin 2 of the VRV, if the low part of the PWM (pulse width modulated) waveform there doesn't pull close to ground and it does pull to ground with the oscilloscope at the ECU pin, that would also indicate a harness/connector problem. It may indicate insufficient drive current for the VRV (not due to the ECU, but due to an ageing harness or connector or corroded/dirty connector). ....still more likely to be a soot/mechanical problem. It sounds like 999dai is at the end of his tether with this issue and feels that he has already spent an inordinate amount of time and money trying to find the fault.
If he's gonna get rid of the car on the assumption that it's an ECU fault then for the value of, say, a week's turnaround, ECUtesting would tell him definitely whether the ECU is at the root of the problem or not. The assumption that the ECU is the culprit may indeed be flawed and is a simplistic diagnosis but that is exactly why it would be sensible to have it checked by experts. At least then he can make a more informed decision about what to do next.😊
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Post by shcm on Jun 26, 2020 18:08:17 GMT
For the sake of even disconnecting two connectors and putting a DVM across the two ends, that's got to be worth a try before splashing out cash on a test. Heck, what would I know. 30 years ECU design and development experience clearly isn't enough. Try to help, by suggesting lower cost eliminations first, but why bother. Good luck, I give up...........
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999dai
Junior Member
Hi all, Really hope someone can help
Posts: 9
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Post by 999dai on Jun 26, 2020 19:33:36 GMT
sorry to cause a fuss guys but all the tech talk is way out of my depth, and to be honest when I try to get someone to have a look to try and diagnose, they're not interested as the time taken isn't cost effective in their eyes. they're only interested in a straight swap of parts which is why I've tried to eliminate one by one at great expense may I add. if I were more capable I'm sure the technical jargon would mean something to me but to be honest I have no clue what any of it means but thanks for the advise. If I could find someone remotely interested in having a go at fixing it the tech info would probably mean something to them but haven't had any luck on that score either.
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999dai
Junior Member
Hi all, Really hope someone can help
Posts: 9
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Post by 999dai on Jun 26, 2020 19:35:14 GMT
Im based in South Wales
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Post by three5 on Jun 26, 2020 19:36:21 GMT
For the sake of even disconnecting two connectors and putting a DVM across the two ends, that's got to be worth a try before splashing out cash on a test. Heck, what would I know. 30 years ECU design and development experience clearly isn't enough. Try to help, by suggesting lower cost eliminations first, but why bother. Good luck, I give up........... The only time I have had a problem anything like this it was a connector to the ECU that wasn't seated properly ( goodness knows why! ) and it had allowed water into it. If I'd have read your reply to this thread, the first thing I'd have done was check the connectors
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Post by three5 on Jun 26, 2020 19:41:56 GMT
I'm in West Yorkshire and I found an excellent diesel specialist ( Feather Diesel services ) just off the M62 at Elland. In your shoes, I'd look for someone like them a bit more local to you. Feathers have millions of pounds worth of test equipment and facilities and were dead easy to deal with.
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