P1252 (unknown fault) 2004 land cruiser

[Dangermouse243]

Hi, I recently had fault code P1252 come up with the yellow engine management light. To start with it only came on once vehicle was warm but now it's on all the time. Toyota say that the code doesn't exist but it clearly does as I have the code logged! If anybody can give me any help or advice I'd be very grateful 

 

 

[RUToyota]

Dunno if any of this may be of help.

Description OBD-II Trouble Code Description for P1252 Toyota Pedal Correlation PDS1 and LPDS High OBD-II Trouble Code Description for P1252 Toyota Pressure Regulator Control Solenoid Valve No. 2 Circuit Malfunction. Kia OBD-II Trouble Code Description for P1252 Toyota Pressure Regulator Control Solenoid Valve No. 2 Circuit Malfunction OBD-II Trouble Code Description for P1252 Toyota Pressure…

CategoriesTOYOTA

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P1252 Toyota OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.

[Dangermouse243]

Thanks for reply, do you know what year those code descriptions are for? My vehicle is 2004 and local Toyota garage say there wasn't a P1252 code number listed on that year, that's where the confusion is arising? 

[RUToyota]

Sorry, can't tell you any more than is there......I think I'd take the easiest route first and clean the MAF sensor..?

[Dangermouse243]

Cleaned MAF sensor and manifold inlet air temp sender and no difference, checked vacuum solenoid which all seem ok, I’m at a total loss now and have it booked in with a different Toyota dealer this Friday so.... watch this space! Lol 

[RUToyota]

Good luck...let us know the outcome.

[syncview]

Hi, sorry to dig an old thread - was the p1252 ever resolved?

[flash22]

OP hasn't posted on here in nearly 3 years

diesel or petrol ? And this is for a landcruiser ?

If It's Diesel, it's either the VNT vanes have seized or the stepper motor aka VNT actuator has gone bad (caused by the first issue) either way it's a turbo off job rebuild or replacement

 

edit. Just found this https://www.picoauto.com/library/case-studies/the-picoscope-journey

[syncview]

Its for a Hilux Surf 2004 with 1KD

And its not that simple, I'm getting p1252 step motor for turbocharger control circuit (open/short)

There is no open or short circuit in the wiring, the wiring loom has been checked twice - turbocharger replaced, map replace, maf replaced, engine ecu swapped with a good known ecu, turbo driver ecu swapped with a good known - nothing works - sometimes the error goes away and the vehicle runs fine, other times it won't even get cleared by a scantool which in the first place led me to believe that its a wiring problem, I have checked the canbus for noise as well using a scope to no avail

[syncview]

An update - for those who may be interested

P1252 error code was resolved by replacing the turbo driver ecu, apparently the one we tested with before was bad aswell and it made the problem run rings around us. But during the process we also learned that the three or six wires from the vnt lever position sensor also make p1252 popup if they are old (high resistance) and of course if one or two of them are disconnected.