Location of VVT-i oil control valve filter screen.
I have a 2003 Highlander with a 4 cylinder engine, 74K miles. Check engine light came on, went to AutoZone for readout. Verbatim from the printout... Code is: P1346, VVT sensor/ camshaft position circuit
Performance fault- bank 1.
1. -Open or short circuit condition
2. -Poor electrical connection
So I bought a Chilton manual for 1999-2006 Highlanders and Lexus RX300/330. Chilton says it's most likely a clogged VVTi Oil Control Valve (OCV) Filter screen, and that it is at rear of cylinder head. Does not say WHERE on the rear of the cylinder head. I DO know where the Oil Control VALVE is, from Chilton's nice photo. SO... does anybody know where Toyota hid the filter for this OCV? I did remove the connector on the OCV and looked at it, no electrical issues visible, it wasn't loose at all. I will check and clean the filter (once I FIND it.) If that doesn't work, then I test out the OCV continuity and resistance. What is the normal resistance for the OCV? This problem developed gradually, sometimes it would go away on its own. I use Mobile1 motor oil, and did an oil change after this problem showed up. After reading all the posts I saw no one else with this problem. Hopefully, that's a good thing.
Isn't the camshaft position sensor and the oil control valve two different parts, one sense the cam position and the other change the valve timing. According to what you have posted, the code is for the cam position sensor not the oil control valve. The cam position sensor, I believe is located on the opposite end of the cylinder head, comparing to the oil control valve which is at the front end of the head/engine.
BTW, the filter, I think since I can't be sure, is behind a plug about half way down the back side of the block by the timing cover area.
Last edited by new echo owner; 10-15-2008 at 01:47 AM.
From what the printout says, you are right. And, I called a Toyota dealer repairman who said the OCV filter was down near the power steering pulley, under a plug with a hex socket. I crawled under the engine and found what he described, but it is blocked by the power steering pump body. I might have to move the pump to pull the filter, no fun! So, I looked in the Chilton book for the camshaft position (CMP) sensor info, and found it in chapter 6 for emissions and engine control systems. This sounds a lot easier. The CMP is at the tranny end of the head like you said, near the "left end of the intake camshaft." That sensor is a pick-up coil, which should be very reliable in function. I will check its connection first and go from there. Thank you very much for the info, N.E.O. I will report my findings later.
I dis-connected the - battery cable to try cancelling the 'check engine' warning light, it failed to fix it. Then I took off the plastic cover over the valve cover and found the connecter for the Cam Shaft Position sensor. I used a pair of pliers to collapse the connector retainer clip and remove the connector. The connector was clean, so I pulled the sensor. The sensor was covered with black crud, like burnt oil. I used some rubber cleaner to clean the sensor and electrical cleaner to clean the contacts. I re-installed the sensor and fired it up. Still had the warning light. So I tried disconnecting the battery again. Voila! No light now! I took some clear photos of the sensor and the crud that was removed, should I post them to help other people find this sensor?
I cleaned off everything and reinstalled the sensor. No change, so I disconnected the battery again to clear the error. Now, the "check engine' light stayed off. Yippee, I thought. A couple days later, the light was on again. So, the resistance of this sensor is 1.115K ohms. Isn't that a little high for a coil? What is the spec for the sensor resistance? AutoZone didn't have a new sensor to compare resistance with. And where can I find all those little specs for sensors like this one to test them with?
Last edited by 23rest; 10-21-2008 at 06:59 PM.
Reason: found previous post, need to shorten new message.
I don't know what 'freeze frame data' is, it's not on the AutoZone printout. A dealer said the spec for the sensor resistance is 800/1400 ohms. Mine varies from 1109 to 1135 ohms, maybe different temperatures? Anyway, I took a photo of what I think is the plug for the VVT-i cam position control valve filter screen. If this is the filter, I HAVE to remove the power steering pump to access it. The Chilton's manual says I need to remove fender splash guards and the right side engine cover to get at the Steering pump. I prefer spending $60 for a sensor to spending a whole day uninstalling / re-installing the power steering pump. I will post the photo as soon as I learn how to do it.
The 'freeze frame data' is the data that the ECM retained when the code was set; in some cases, it will tell you if the engine was cold or hot, and at what rpm. In other words, if the code was set when it was cold, and you are doing you test when it is warm, the condition might not show up.
There was indeed two different set of resistance reading for the sensor. I don't feel the VVTi filter screen is plugged, because it would have set the VVTi actuator code instead of the cam position sensor code. And I would agree that for $60, it would be well worth spending if there is any chance that would fix your problem.
I created my own gallery and posted my 1st photo there. It is a shot of the back side of the engine showing the power steering pump body and what I think is the plug for the filter screen for the Cam position control valve. Is the blue arrow is pointing to the filter plug? Here is a link to that photo: http://www.toyotanation.com/photos/s.../ppuser/159164
As you can see, there is NO getting a hex wrench in that hole with the steering pump in place! NOT a good design for servicing! I will order the sensor tomorrow.
The 'check engine' light came on again a day after I changed the cam position sensor. The new sensor is an exact copy of the old one, it has the same numbers and 'Toyota' stamped on its side. I guess it's another defective wire in the system. Last year a mechanic charged me $110 to find and change a bad wire to the air conditioner. That was a good price for getting it done right the first time. Unless someone has a better idea, I will have to go back to this guy. The connectors on the computer behind the glove box were ok. The vehicle has 74k miles on it.
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