307 1.6 hdi 90 hp - P0238 Anti Pollution Fault

[307pugpete]

Treat the Pug to a full service today and noticed it smokes a bit and to be fair the emission's stink quite acrid , after taking it a drive around the block and driving up hill in second with high revs in an attempt to clear it the Anti Pollution light came on and wording in central console display. fault code P0238 -Turbocharger Boost Sensor A Circuit High (taken from red brick snap on scanner mt2500) once cleared and reran it came back on again !! 6 hours of googling and im no closer , car is a 90bhp 1.6 hdi

Bit of history - car is a 2006 90hp 1.6 hdi light front end damage in September 2010 and hasnt been driven since only light idleing , today is the first time it was driven.

Looking at the internet it could be turbo solenoid (anyone know where this is?) however noticed a poster who said a loose air filter pipe (air filter element renewed today) also changed the fuel filter and it was a bugger to prime and took ages to start , now takes a few cranks to turn over when it was pretty rapid before.

Any help or advice would be much appreciated

UPDATE-

The fault only occurs at exactly 2700rpm every time and it suffers no degraded performance , pick up is exactly the same as before.

All air filter pipes checked and rechecked as tight and car starts as it should now after bleeding through the new fuel filter.

Iv read that it could be the turbo boost solenoid , is this the one on the top of the rad with 2 vac pipes and a grey multiplug? If so i removed this and ran the car , it behaved exactly the same as before with no degraded performance and the light came on as the car reached 2700rpm - interesting to note that the car needs to be driven to register the fault and mostly up a hill , it will sit still and be revved beyond 4000rpm no problems it appears its when there is a load on the engine.

Any pointers or help would be most appreciated as im slowly losing the will to live

[davidireland]

Turbo solenoid valve at back of engine above the driveshaft.

[307pugpete]

Thanks David , does it have just a wiring plug? (easy to spot?) Iv tried to google an image but cant find one anywhere. In your opinion does the fault sound like it could be this?

[Hysteria]

Check your error codes.

If they contain the following you probably have a small leak (sucking in air) in your fuel lines. You can suck in air in a diesel because the fuel is fed to the engine on vacume principle

Error Codes
P0087.
P0093.
P1113.

It's possible that it's also an injector but given what I have read on multiple forums the culprid seems to be (90% of the time) a fuel feed line or associated part.

An alternative is the fuel filter becomming blocked.

Either problem will cause your engine to go nuts, especially the motor managment.

Either problem will also cause your engine to cutout/shut down.

[davidireland]

This is not an injector or fuel problem. Its a turbo overboost problem. This engine has a fixed geometry turbo. I'd be looking at the vacuum circuit first. check the breather to the turbo solenoid valve. It is under the plastic cover on top of the engine. Make sure there is no soot around it.

[thirdwatch]

Ive had the same problem for some time now.Almost every journey i made to work approx 16 miles away the engine management light came on. But after switching on/off for 4 or 5 times the light would switch off.
I have a peugeot 407 sw on a 56 plate. I first checked the air filter which was ok but when i removed the small engine cover i noticed carbon deposits around one of the injectors. After starting up the engine there was blowing from this injector. After further investigation the injector was loose and after tightning the blowing stopped.
Took car for a run and yes the depollution message came on .Now i was not prepared to take car to peugeot and give them £50 - £60 to tell me the fault codes so bought machine,plugged it in and found code P0238 cleared code and has not returned.