P1251 Overboost Problem With Rav4 D4-D

[bacongrabber]

Hi all.

I'm getting an overboost problem with my 56 (late 2006) plate Rav4 (130,000 miles).

I've monitored the turbo pressure whilst driving and its going above 20psi when pressed. (I think it should only be max 14?). The fault was intermittent at first but now is constant and will go into limp mode if pushed hard.

I've tested both vacuum valves which seem to be operating correctly. I'm guessing that the problem is with the e-vrv (turbo pressure regulator valve). I've tested the e-vrv using 6V and it seems to be passing pressure correctly. There is plenty of vacuum pressure before the e-vrv and also the wastegate valve seems to be operating correctly when I attach a pipe to the wastegate actuator and suck. I've attached a meter and an oscilloscope to the e-vrv loom connector whilst the engine is running but there doesn't seem to be a signal (should it be a DC voltage or a waveform?).

My question is:

I can't wind any wiring diagrams for the ECU or e-vrv valve for this model. From which pin on the ECU does the e-vrv receive its signal? The wires on the valve are both black with a red stripe so no help in tracing them there. Can anyone send me or point me to one?

A quick response would be very much appreciated. My wife wants to go shopping!

Many thanks,

John.