D-4d Error P1250 Turbocharger System Malfunction

[millsy747]

Hello All,

i am a new member, so first of all i would just like to say hello to everyone.

We brought a 2001 rav4 d-4d vx 5 door approx 2 months ago and all had been running fine apart from a squeaky fan belt which was replaced about 3 weeks ago, about a week after the fan belt was replaced i was overtaking a lorry and the mil light came on then the rav went into limp mode (dropped to about 10mph) l managed to get it over to the hard shoulder, i turned the ignition off and then on again and the mil light was now off, i put this down to a glitch but the same problem happened a week later this time i thought about what was happening before the mil light came on, i was accelerating above 3500 revs and overtaking, exactly the same as previous.

I managed to get the error code from the rav which was P1250 Turbocharger System Malfunction, these were the only 2 errors that were held in the rav, so i am just wondering if when the garage changed the fan belt they could have knocked something that may have caused the error. I have also read a few posts on the forum that have displayed similar symptoms to the ones i have described but they have had different error codes and to be honest some of the stories i have read about problems with the turbocharger and the amount of money people have spent trying to resolve the problem scares me, so any advice welcomed.

[anchorman]

Hello All,

i am a new member, so first of all i would just like to say hello to everyone.

We brought a 2001 rav4 d-4d vx 5 door approx 2 months ago and all had been running fine apart from a squeaky fan belt which was replaced about 3 weeks ago, about a week after the fan belt was replaced i was overtaking a lorry and the mil light came on then the rav went into limp mode (dropped to about 10mph) l managed to get it over to the hard shoulder, i turned the ignition off and then on again and the mil light was now off, i put this down to a glitch but the same problem happened a week later this time i thought about what was happening before the mil light came on, i was accelerating above 3500 revs and overtaking, exactly the same as previous.

I managed to get the error code from the rav which was P1250 Turbocharger System Malfunction, these were the only 2 errors that were held in the rav, so i am just wondering if when the garage changed the fan belt they could have knocked something that may have caused the error. I have also read a few posts on the forum that have displayed similar symptoms to the ones i have described but they have had different error codes and to be honest some of the stories i have read about problems with the turbocharger and the amount of money people have spent trying to resolve the problem scares me, so any advice welcomed.

Welcome to the club Millsy.

I have to be up very early in the morn so will come back later tomorrow if somebody else hasn't done so.

Sit tight!

[anchorman]

I managed to get the error code from the rav which was P1250 Turbocharger System Malfunction, these were the only 2 errors that were held in the rav

Firstly, what do you mean 2 errors?

P1250 is one of those codes that pops up now and again but isn't listed in the standard code lists for the RAV. I think it is telling you that there is an "over boost" condition. In this case you should check all the vacuum hoses in the turbo circuit and then turn your attention to the vsv (vacuum sensing valve) which is located just to the right of the intercooler as you look under the bonnet (between the engine and the air filter).

vsv.pdf

vsv_test.pdf

Have a look at these and let us know how you get on.

[Turps]

I had same symptoms and exact same error code. Thinking it was going to be a big job so until I had time to look at the problem I managed to continue driving it around not exceeding 2000 RPM and switching off and restarting when it did happen. (whilst I was doing this I had noticeably better fuel economy)

My mechanic friend who diagnosed it for me told me that the diagnostic report "P1250 Turbocharger System Malfunction" could be anything on the turbo system (including vacuum sensing valve mentioned by anchorman) but my friends best guess was the turbo wastegate was sticking creating overboost. Not wanting to go straight in and take off the turbo, I took off the intercooler to get better access to the turbo. Undid the 2 bolts attaching the wastegate actuator, and worked the linkage to make sure it was free then lubed the moving parts and put it all back together. Sorted all back up and running with no problems in an hour. See the photo of actuator and linkage I have circled the areas I lubed.

If the error reoccurs and depending on how long this quick fix lasts, I will replace the actuator if that doesn’t fix it I will take out the turbo and look at the actual wastegate flap.

Hope this helps.

[Dantag]

I managed to get the error code from the rav which was P1250 Turbocharger System Malfunction, these were the only 2 errors that were held in the rav

Firstly, what do you mean 2 errors?

P1250 is one of those codes that pops up now and again but isn't listed in the standard code lists for the RAV. I think it is telling you that there is an "over boost" condition. In this case you should check all the vacuum hoses in the turbo circuit and then turn your attention to the vsv (vacuum sensing valve) which is located just to the right of the intercooler as you look under the bonnet (between the engine and the air filter).

vsv.pdf

vsv_test.pdf

Have a look at these and let us know how you get on.

Hi

I am also experiencing the same fault. I am an experienced hgv tech but not familiar with the turbo/vac system on this car. The vac actuator on the turbo is moving freely and on tick over the arm moves straight to the up position. Should there be a vacuum at all times to the turbo actuator from the vsv?

Any help would be greatly received.

Cheers

Dan

[peso]

Hi. I am new to this forum, an this is my first post. Im from Norway, so please forgive my mispelling.

I know that this is an old tread, but im still hoping to get an answer.

I have a massive loss of engine power, an engine fault lamp is on. (2005 mod Raw4 2.0 D4D with short milage.)

Had exactly same sympoms last year, and when the dealer replaced the scv valve, the engine operated fine.

Now the problem is back, and im suspecting the vsv.

I downloaded and tested acording to "test vsv"

when disconnected , It says that air should NOT flow between E and G, i s this correct?

mine have free flow between these ports, and when connected to Battery, it opens from E to the filter.

Help, anyone?

[anchorman]

Yes that pdf is wrong. It actually should flow the opposite way. Find a small piece of pipe to bypass it all together and see how it drives.

Oh and welcome to the club.

[peso]

Hi, thanks for the reply.

I went to my Toyotadealer yesterday, and the faultcode indicated that it was the SCV valve, again.

There was a one year warranty on the valve, it had 6 days left. :-)

so now it runs ok, and best of all that i didnt have to pay anything, this time.

But im a little concerned now, 2 times in one year, hmmm.

Peso

[Iaino19]

Hi all? I have been experiencing overboost problems with our Rav4 for sometime now but only when towing, replaced the water pump & timing belt aug 13 and found the cps encased in corrosion from the leaking pump, car was running great no problems towing until lasf friday when it started the problem again! I dont think the fault is with the turbo charger as it wouldn't have lasted approximately a year and a half from the problem occurred, I've done the vsv valve test getting no reading across the terminals and when I put 12v it click's, is this normal and air seems to flow both ways! Please help to resolve my problem.

[Bodgit-fixit-run]

Yep I get it when towing. I thinks it's almost impossible to definitively pin this one down. I' gone through the whole gambit including rebuilding the turbo. Theres a small valve above the egr valve. Spray into it with wd40 or similar and see what that does. Just watch your revs around 2300 when towing and avoid 5th gear. I find that helps a lot. I also carry a fault code reader and clear the code when it comes up, I then just carry on.

[Iaino19]

I rang toyota parts today about the vsv valve price I nearly dropped the phone around the £440 + vat the turbo pressure sensor is over £200+ vat, I wud need to make sure the fault is with 1 of these parts b4 buying! Its so frustrating when towing never happens any other time I will try a spray of carb cleaner in the sensor see how it goes nxt wk end. Thanks for ur help.

[aj11r]

Hi all, we have had this same fault happen again. Even after having this last year and toyota fitting a whole new turbo!! Seriously annoyed now!

[Bodgit-fixit-run]

I think it's safe to say it's not the turbo. So many have had this fault yet Mr T doesn't care. I've had it for over 70k now and still not found the actual definitive cause.

[Simon 1010]

Hello.

I to am having the same fault P1251 on my 2005 d4d. I am pretty sure its not the turbo as I have stripped this down and theres absolutely no sign of sticking in the vanes. and the control arm etc are all moving freely. This all started happening after I fitted a unipart air filter last year. I have just ran some wynns turbo cleaner through from the air intake, cleaned the MAF sensor and am putting some comma diesel magic through the tank. I will strip down the turbo vsv circuit and pipes to check next. I find it hard to believe that there are thousands of Toyota Rav4's all with average miles and faulty turbos.

[Simon 1010]

Hello.

I to am having the same fault P1251 on my 2005 d4d. I am pretty sure its not the turbo as I have stripped this down and theres absolutely no sign of sticking in the vanes. and the control arm etc are all moving freely. This all started happening after I fitted a unipart air filter last year. I have just ran some wynns turbo cleaner through from the air intake, cleaned the MAF sensor and am putting some comma diesel magic through the tank. I will strip down the turbo vsv circuit and pipes to check next. I find it hard to believe that there are thousands of Toyota Rav4's all with average miles and faulty turbos.

Just an update.

I took my car out last night after running the wynns turbo cleaner through it and gave it a good uphill run to the redline. There was a large burst of smoke and then it cleared up after a couple of runs up the hill. Today I rechecked the resistance of the MAF sensor and its sitting correct at 2.6K ohms. There was initially allot of corrosion and grim the MAF hot wire and temp sensor that have all cleaned off with a good clean of carb cleaner. Today I took it for another hill run with the air filter removed from the filter box (this allowed me to hear the response from the turbo spooling up and down). Its pulling great from even low revs in 5th right up to full torque above 2000 rpm. As my wife has been the main driver in this car from new its very likely that the P1251 code ever six months could have been down to sooting up from 80,000 round town gentle miles and it really just needed a good hard run.

I will update again soon (leaving the vsv for now).

[Simon 1010]

Hello.

I to am having the same fault P1251 on my 2005 d4d. I am pretty sure its not the turbo as I have stripped this down and theres absolutely no sign of sticking in the vanes. and the control arm etc are all moving freely. This all started happening after I fitted a unipart air filter last year. I have just ran some wynns turbo cleaner through from the air intake, cleaned the MAF sensor and am putting some comma diesel magic through the tank. I will strip down the turbo vsv circuit and pipes to check next. I find it hard to believe that there are thousands of Toyota Rav4's all with average miles and faulty turbos.

Just an update.

I took my car out last night after running the wynns turbo cleaner through it and gave it a good uphill run to the redline. There was a large burst of smoke and then it cleared up after a couple of runs up the hill. Today I rechecked the resistance of the MAF sensor and its sitting correct at 2.6K ohms. There was initially allot of corrosion and grim the MAF hot wire and temp sensor that have all cleaned off with a good clean of carb cleaner. Today I took it for another hill run with the air filter removed from the filter box (this allowed me to hear the response from the turbo spooling up and down). Its pulling great from even low revs in 5th right up to full torque above 2000 rpm. As my wife has been the main driver in this car from new its very likely that the P1251 code ever six months could have been down to sooting up from 80,000 round town gentle miles and it really just needed a good hard run.

I will update again soon (leaving the vsv for now).

[Iaino19]

Update on my progress on this never ending problem with overboost issue!! On trawling the net I found a peoduct called revive used in aviation industry to clean jet engine now being used in the motor industry to clean carbon build up in turbo chargers (sticking vanes). This is a 3 stage process that is simply sprayed into the intake well I thought I'd give it a try found a local supplier in N Ireland that actually delivered it to my work for me. After I carried out this procedure I took the car for a brisk drive and it was going a lot better but had it cured my overboost problem time will tell when I head off on our next trip away with the caravan? Well perfect run to our destination Happy days hopefully the return will be the same! On the way back on the outside lane of the motorway passing an on-slip well no power on comes tge eml not good trying to make your way to the hard shoulder my problem was still there!! So after more research I have now replaced tge turbo with a recon unit as the rav4 suffers this problem is down to the variable vanes sticking as the toytota cars don't incure this trouble. The job of replacing the turbo is not for the faint hearted may I say bolts holding bolts just typical toyota now the car is going a lot better with a much more improved mid range the rav will actually sit at abt 40 (on the speedo actually 36) in 5th gear and will pull away without going down a gear, so heading away on a much longer trip today and hopefully the problem will be cured or I've just spent £300 for no reason!! Will keep you's updated.

[redlew]

P1251 faults (as opposed to P1250) are covered at

http://www.toyotaownersclub.com/forums/topic/100563-turbo-recon/

http://www.toyotaownersclub.com/forums/topic/75890-d4d-engine-fault/ post 36 scary

http://www.toyotaownersclub.com/forums/topic/77292-previa-turbo-failure/

The upshot seems to be that the answer can be turbo , VSV , VSC , leaks in the pipe/hoses or injectors and no clear way to decide what it is .

Is there a pecking order?

[sich1]

something to think about....

decided to have a play with the pipes on the vsv. joined up the 2 pipes on the right of the picture with a small connector and took the car for a spin.....still hesitating above 2200 rpm.

put them back where they should be and this evening the car was perfect!! no hesitation and smooth acceleration all the way.....?.......makes me think the vsv is a bit iffy.

but i will enjoy the smoothness while it lasts,not having to worry about lack of power is nice again.

still ok this AM 14/7

1 hiccup PM 14/7

only one hesitation today 16/7

[mazzy]

hi everyone i also have this intermittent turbo problem .havnt checked anything yet, only difference i can see with mine is my engine management light doesnt come on .but i did try something that some one told me and that is to not go above 3000 revs and apparently the limp mode cant kick in .so i tryed it yesterday and either the rav had a good day, or it works .ok its not a fix but temporarily sstops the limp mode .

[Iaino19]

After a 2hr drive on Saturday morning with the caravan on we made a trouble free journey,this included a 4th uphill challenge at abt 45mph the rav4 climbed it the best ever!! On the motorway I actually had to lift off due to the pull in 5th gear!! We had this problem for approximitly 2 yrs trawled trough loads of forums checked different valves & sensors and at the last resort it was time to replace the turbocharger, best move as I'm very happy with the cars performance now (drives like a new 1) even with 105k!! If your rav is going into limp mode with overboost code it is more than likely the variable vanes sticking.

[Iaino19]

After a faultless return journey from our hoilday I can now say that the overboost problems are well and truly a thing of the past rav4 is pulling extremely well under load when towing the caravan!!

[golfer456]

Hi - just thought I would give my experience of having the same issues many have described here, going into limp mode and P1250. Phoned an independent Toyota garage (Toyoda Tech) and Stuart spent 1/2 hr chatting over the symptoms before advising in his opinion that the turbo was gone and recommending a replacement for the princely sum of £2300 all in (new turbo). Having seen many posts and think what have I got to loss decided to "Mr Muscle" clean the turbo.

It took nearly 3 hours to get to the point where I could get at the back of the turbo but used about 1/2 a can of Mr Muscle oven cleaner and left it in there for approx 1 1/2 hours and then cleaned it out with carb cleaner.

Put everything back together next morning and cleaned everything on the vacuum side and new piping.

Result - drives like new !!!

No hesitation, accelerates like it did 60,000 miles ago. So before parting with your cash at least give this a go, nothing to loss !!!

Cheers

Mark

[mercedesjenz]

On 15/07/2014 at 8:41 AM, Iaino19 said:

After a 2hr drive on Saturday morning with the caravan on we made a trouble free journey,this included a 4th uphill challenge at abt 45mph the rav4 climbed it the best ever!! On the motorway I actually had to lift off due to the pull in 5th gear!! We had this problem for approximitly 2 yrs trawled trough loads of forums checked different valves & sensors and at the last resort it was time to replace the turbocharger, best move as I'm very happy with the cars performance now (drives like a new 1) even with 105k!! If your rav is going into limp mode with overboost code it is more than likely the variable vanes sticking.

I know this thread is probably older than me by now but just to say, it has helped me with sorting my overboost problem out. My Previa had a spurious turbo when I bought it, changed it to a second hand original as that spurious one made an awful racket. With the new second hand turbo got the overboost problem. So off it came and stripped down it was, all cleaned, vacuum linkage lubed, egr cleaned, too. Now I know how a d4d should drive.  All lovely. Thanks folks. (BTW folks on here also helped with the blow-by problem, a good clean and new upgraded injector seals from Mr T helped)

[mercedesjenz]

Oh, I forgot:  This is why I wanted to reply, apart from saying Thank You.  I did check the "new" turbo before fitting it.  It APPEARED to be moving freely when unbolting the vacuum unit and moving the lever.  Then I got the overboost problem, so had to take it off again, strip it and clean it, which sorted the problem. So, even if you THINK it is ok, it sometimes isn't, as a little buildup of soot can stop the vanes from working properly.

My guess is that the car my second hand turbo came off was scrapped because of the sticky vanes, which would have been a waste of an otherwise good car.