D4D Running Issue

[A1an]

The Rav4 is playing up again, its a bit of an intermittent running fault.

Whilst driving along the car will lose all power and the EML comes on, strangely the VSC light comes on too. The car will idle fine but when you put the foot down the revs wont climb. If you pull over, turn engine off and then restart it runs perfectly and will do for many days before the fault appears again.

Any ideas?

I have a code reader and was thinking of trying it to see what is stored but cant find the plug on the car?

[Cyker]

Is the power-loss just because the real fault is causing the car to go into 'limp' mode, or is it actually part of the problem?

[Lupidog]

the ESC indicates a sensor failure.... The VSC could be the sensor failure. Sooooo does loss of VSC put the car into limp mode ... anyone?

[A1an]

OK, Ive been out and read the codes...P1251, its looking like this is pointing towards a turbo overboost issue.

As I understand it the D4D uses a variable vane turbo controlled by VSV's, I have a sneeky suspicion that these valves may be causing stick vanes.

Il do a bit more digging.

[A1an]

the ESC indicates a sensor failure.... The VSC could be the sensor failure. Sooooo does loss of VSC put the car into limp mode ... anyone?

I think the VSC light is just a quirk of the problem, I had a similar issue in a vectra that when the Idle Air Control Valve went it threw up the TC light!

What the car does is NOT go into limp mode, its the fault that is causing the running issue, limp mode is a "get you home mode", reduced power but will get you out of bother. My problem wouldnt get you off the road.

[Lupidog]

Surely the vanes can't close off completely. You would always have some intake airflow and exhaust outlet, which would allow very slow acceleration. If it,s a mechanical problem, it wouldn't go away by stopping and starting the engine. The EMS must have its grubby little hands dirty on this one. This never happened on my Morris Oxford.

[A1an]

Surely the vanes can't close off completely. You would always have some intake airflow and exhaust outlet, which would allow very slow acceleration. If it,s a mechanical problem, it wouldn't go away by stopping and starting the engine. The EMS must have its grubby little hands dirty on this one. This never happened on my Morris Oxford.

I would say it is possibly an electrical problem connected to over boosting, the vanes could be sticking open causing it to continuely feeding full boost?

Is there a boost pressure sensor?

[A1an]

I have been reading a bit on here and the general concensus is that the turbo doesnt have a wastegate but a small black box contaning the VSV, my turbo has a definate wastegate controlled by what looks like a vacuum pipe.

Could it be a sticky wastegate?

[Parts-King]

SCV Valves?

http://www.toyotaownersclub.com/forums/index.php?showtopic=87986

Kingo

[igormus]

Surely the vanes can't close off completely. You would always have some intake airflow and exhaust outlet, which would allow very slow acceleration. If it,s a mechanical problem, it wouldn't go away by stopping and starting the engine. The EMS must have its grubby little hands dirty on this one. This never happened on my Morris Oxford.

I would say it is possibly an electrical problem connected to over boosting, the vanes could be sticking open causing it to continuely feeding full boost?

Is there a boost pressure sensor?

hi mate

the turbocharger is provided either with pressure sensor giving a comand to VSC or the VSC itself acts as safety valve to prevent suction manifold from over pressure. Cheers/Igor

[anchorman]

Turbo overboost. I would look towards the VSV

Safe mode.pdf

[A1an]

Turbo overboost. I would look towards the VSV

Safe mode.pdf

Is there a how2 anywhere for the VSV's?

Can you give any advice?

[Wycheee1970]

I'm having the same fault an have changed the vsv but it's made no difference the garage are looking towards an egr fault. Very frustrating.

[*srjp*]

Had similar problem/symptoms, most noticeable making good progress uphill in the cold :Lights come on and car has no power. Turn off and on again and pulls away fine, EML stays on (you can clear it by disconnecting the Battery briefly).

I cleaned the EGR valve using the helpful guide on here but the problem occurred again (in total it happened maybe five times over the winter).

Last week, I took the car to a diesel specialist who said the fault code was a bit vague but the likely problem was the two "Pressure Regulator Valves" so both these have now been replaced. We couldn't recreate the original conditions of the winter driving, but the car does already seem to pull more enthusiastically and the other occasional hesitation on overtaking etc (which I liken to the kickdown delay in an automatic) seems to have gone too. Fingers crossed...