I have posted this on ToyotaNation Camry area too.
I have 1999 4cyl LE. I have read all of the threads on this particular topic but still do not know what to do now. I started getting P0446 since last month and the code comes back immediately after resetting it. My mechanic says he sees a lot of them on Camry and Corolla and replacing the rear VSV solenoid fixes it. He had a genuine Toyota part in stock but after he removed mine, realized that mine had three hoses and the one he had was the one with the two hoses variant. So we got the correct one from NAPA.
Well, the code came back in couple of trips.
Is it possible that could it be a bad NAPA part? I can ask him to get the genuine Toyota part but if that does not fix it, then my leverage on him will be reduced greatly. He will do whatever I ask him but then I have to be better diagnostician than he is. Right now he has thrown a part at it based upon his previous experience. Having read this forum, I sort of knew going in that I would have to be really lucky if only VSV was going to fix it but I decided to take a chance.
I have put my EOBD scanner on the car. The Mode $06 data shows all of the six test being completed successfully. Unfortunately, I do not have the decoding ring for Toyota 1999 Mode $06 to interpret them. On the I/M, everything except EVAP MON is incomplete and the CEL must be going off when that test is being attempted to run. My mechanic's fancy scanner is down and he won't get it for at least another week or so. Mine is adequate but does not have factory support or two way testing.
Given the specificity of the code i.e. circuit fault, I did not even bother to get a new gas cap as I am thinking it would have no chance of causing this particular error code but then I do not know what the Toyota engineers were thinking when they wrote their ECM code. At this stage I am desperate. Should I just throw a brand new OEM cap at it? It surely can use a new cap after 13 years of faithful service but is there even a remote chance that would fix the P0446 code?
I have got lots of tools such as electronic copy of factory service manual, generic scanner, mightyvac vacuum pump with gauge, dmm etc but the limitation is I do NOT work under the car unless it is on the lift.
How would ScannerDanner or ScottyKilmer or EricTheCarGuy would approach this one i.e. real diagnosis vs parts replacement? I would rather not follow any algorithm which is of type
1) Replace part A
2) Did it fix the problem?
Yes - Done
No - go to 3
3) Replace part B
..
Some of the factory service procedures are like that. I know some of you have lot of experience on this specific problem and I hope they consider this one as an internet challenge!
Update:-
I just bench tested the older VSV. It works fine. It holds the vacuum on one port and the other is flow through. There are no leakage. Vacuum is released when the voltage is applied. It passes all the test listed in the service manual.
This means there was no need to replace that VSV and something else is the cause of the P0446
I have 1999 4cyl LE. I have read all of the threads on this particular topic but still do not know what to do now. I started getting P0446 since last month and the code comes back immediately after resetting it. My mechanic says he sees a lot of them on Camry and Corolla and replacing the rear VSV solenoid fixes it. He had a genuine Toyota part in stock but after he removed mine, realized that mine had three hoses and the one he had was the one with the two hoses variant. So we got the correct one from NAPA.
Well, the code came back in couple of trips.
Is it possible that could it be a bad NAPA part? I can ask him to get the genuine Toyota part but if that does not fix it, then my leverage on him will be reduced greatly. He will do whatever I ask him but then I have to be better diagnostician than he is. Right now he has thrown a part at it based upon his previous experience. Having read this forum, I sort of knew going in that I would have to be really lucky if only VSV was going to fix it but I decided to take a chance.
I have put my EOBD scanner on the car. The Mode $06 data shows all of the six test being completed successfully. Unfortunately, I do not have the decoding ring for Toyota 1999 Mode $06 to interpret them. On the I/M, everything except EVAP MON is incomplete and the CEL must be going off when that test is being attempted to run. My mechanic's fancy scanner is down and he won't get it for at least another week or so. Mine is adequate but does not have factory support or two way testing.
Given the specificity of the code i.e. circuit fault, I did not even bother to get a new gas cap as I am thinking it would have no chance of causing this particular error code but then I do not know what the Toyota engineers were thinking when they wrote their ECM code. At this stage I am desperate. Should I just throw a brand new OEM cap at it? It surely can use a new cap after 13 years of faithful service but is there even a remote chance that would fix the P0446 code?
I have got lots of tools such as electronic copy of factory service manual, generic scanner, mightyvac vacuum pump with gauge, dmm etc but the limitation is I do NOT work under the car unless it is on the lift.
How would ScannerDanner or ScottyKilmer or EricTheCarGuy would approach this one i.e. real diagnosis vs parts replacement? I would rather not follow any algorithm which is of type
1) Replace part A
2) Did it fix the problem?
Yes - Done
No - go to 3
3) Replace part B
..
Some of the factory service procedures are like that. I know some of you have lot of experience on this specific problem and I hope they consider this one as an internet challenge!
Update:-
I just bench tested the older VSV. It works fine. It holds the vacuum on one port and the other is flow through. There are no leakage. Vacuum is released when the voltage is applied. It passes all the test listed in the service manual.
This means there was no need to replace that VSV and something else is the cause of the P0446