vettereddie

I recently rebuilt a motor that had blown a head gasket, and replaced it with another used head. Now I'm getting the P0012 code thrown. Searching on here it seems the main culprit is a bad VVT gear on the cam, but right now I'm not so sure.

I have a second xB that hasn't had any issues. I pulled the Oil Control Valve from the good xB and put it in the suspect one. With the "good" sensor, the car wouldn't start even. I then put the OCV back in the good car, and now I'm getting a code in that as well.
Could swapping it make the OCV go bad somehow? Troubleshooting this is becoming a huge pain. I'd like to test it but the troubleshooting guide and TSB say the special Toyota reader is needed, and an oscilloscope to check the waveform from the ECM.

All I have is a basic code reader.

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vettereddie

It's DEFINATELY the OCV and not the cam. I pulled it and hooked it up to 12V from the battery, and felt the solenoid engage but go no movement. I then sprayed in some carb cleaner into the valve, followed by a blow out with shop air. Hooked it back up to the battery and now it gets about 1/4" of travel, for a very noticeable difference. Put the valve back on the head and drove for 20 minutes with no code so far, so I think it was a stuck valve.

Now this issue is where is the grit / contaminate coming from to make it stick. it either picked something up when I set it down to put in the other car, or there is stuff in the other head, which may have picked up some dirt while sitting around a salvage yard for 6 months. When I got it in the intake valves were rusted, and it was obvious it had been in storage sitting with the intake side up, collecting water in the intake but not exhaust. The valves were either polished or replaced, lapped and reseated, but I did not do a full hot tank. Going to go back and check the OCV filter below the actual valve, to see if there is blockage.

Bottom line, if you throw a P0012, don't automatically assume it's the cam gear. It could just be a blocked OCV, easy to test with some wire and the car battery.

AdamRS2

Thank you very much this is very helpful I'm going to try this tomorrow this bloody Code P0012 is driving me nuts
the car will go about a month in between errors but lately it's been much more regularly.

Anything important I should be aware of pulling the OCV or is it as easy as it looks?

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CBSIMONSEZ

Im curious, how the hell do you get that little thing out?

eatcrispycreme2

It's a single 8mm bolt that holds the OCV in place. You will also need to disconnect the sensor.

eatcrispycreme2

I went ahead and made a video because I found very little info out there. This is for the P0012 repair but can help with a few different things if you watch all three parts:

Part 1 Part 2 Part 3 P0012 Fix DIY Scion xB 2004-2006 Part 3/3

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