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HighlanderGeneral discussion forum for the Toyota Highlander and Highlander Hybrid.
This is a discussion thread titled "Flunked Emissions; DTC P0440, 41 & 46", within the Highlander forum, part of the SUV Forums category.
Help, took our 2001 Highlander w/ 53K miles for an emissions test today. It failed because of the following DTC: P0440, P0441 & P0446 The gas cap passed it's test.
It's a 6 cyl/4WD
I'm out of a job and would rather not pay big bucks to the dealer. Any suggestions about causes and corrections?
These codes are related to the fuel tank vapour "Evaporative Emission Control System". P0440 - System Malfunction, P0441 - Incorrect Purge Flow and P0446 - Vent Control Malfunction. I would replace the gas cap first before doing anything else. There're a number of components that can cause this problem (vapour pressure sensor or its wiring, gas cap, vacuum hoses, fuel tank, charcoal canister, VSV (purge solenoid or its wiring) or ECU). The P0440 is set if the vehicle is driven but the fuel tank pressure remains at atmospheric pressure. P0441 is set if the charcoal canister pressure does not drop during purge operation or if during purge cut-off the pressure in the canister is low compare to atmospheric pressure. P0446 is set if the ECM judges that there is no continuity between the VSV and the fuel tank or the VSV and the charcoal canister or that the pressure in the charcoal canister is at atmospheric pressure after the purge cut-off. VSV = purge solenoid.
Help, took our 2001 Highlander w/ 53K miles for an emissions test today. It failed because of the following DTC: P0440, P0441 & P0446 The gas cap passed it's test.
It's a 6 cyl/4WD
I'm out of a job and would rather not pay big bucks to the dealer. Any suggestions about causes and corrections?
Thanks for your help.
P0440 Evaporative Emission Control System Malfunction
Hose or tube cracked, holed, damaged or loose seal
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or disconnected
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Fuel tank over fill check valve cracked or damaged
ECM
P0441 Evaporative Emission Control System Incorrect Purge Flow
Vacuum hose cracked, holed, blocked damaged or disconnected
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Open or short in VSV circuit for pressure switching valve
VSV for pressure switching valve
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
ECM
P0442 Evaporative Emission Control System Malfunction
Same as DTC No. P0440
Thanks for the feedback looks like I have my work cut out for me.
Many people have suggested the gas cap can be the cause of the problem. We did replace the cap when the check engine light originally came on. It (the cap) was tested at the emissions center and passed the test.
The emission test station merely plugged their computer into the car.
Is it possible the code just needs to be cleared or reset? Is there an easy way to reset ie.. disconnect & reconnect the battery?
If the check engine light was not "ON", then it would have been the codes stored by the ECU during the original problem. This problem requires 2 detection trips to illuminate the check engine light. The stored codes can only be reset with a scan tool. If the check engine light is currently "OFF" would mean the fault is no longer there.
I just recently got my highlander and had a similar problem.
My CEL came on and the codes the dealer read where the same as yours.
Turns out there is a vacum hose that attaches to the air filter/ breather housing. This hose is known to come loose causing this fault.
Also I have heard that if you replace the gas cap with a nonstock cap, it may also cause the fault.
As far as clearing the codes, i wish i could help you but i'm not sure how to clear them on a highlander.
FYI - autozone has a code reader that you can borrow/rent to read the codes from you car. I'm not sure, but this might also be able to reset the codes.
Many thanks for the response. I popped the hood and, sure enough, there was an unnattached vaccum hose. I reattached it, put the old original equipment gas cap back on and sailed through emissions without a problem. I wonder how much the dealer would have charged for this 5 minute repair?
Also, FYI from what I've seen in these forums there are two ways to reset the OBD. First disconnect the battery, pulling the negative cable won't effect the radio and other settings. The second is to pull the 20 amp fuse from the underhood fuse box for about 20 seconds. I didn't want to fool around so I did both. One or both worked because the check engine light was out and the emissions test center didn't pick any codes.
Many thanks for the response. I popped the hood and, sure enough, there was an unnattached vaccum hose. I reattached it, put the old original equipment gas cap back on and sailed through emissions without a problem. I wonder how much the dealer would have charged for this 5 minute repair?
Also, FYI from what I've seen in these forums there are two ways to reset the OBD. First disconnect the battery, pulling the negative cable won't effect the radio and other settings. The second is to pull the 20 amp fuse from the underhood fuse box for about 20 seconds. I didn't want to fool around so I did both. One or both worked because the check engine light was out and the emissions test center didn't pick any codes.
THANKS AGAIN!
FYI...Pulling the Negative (-)battery cable OR the Positive (+)battery cable Willreset the radio!!!
Its probably the hose attached at the air filter box as someone else suggested. The guys at the quick lube places knock it off when they check your air filter.
On Friday, 1/26/2007, I had the Express Lube service done on my 2001 Highlander at Longo Toyota. I didn't drive it until Monday, 1/29. Yesterday, 1/31, when I started the car, the MIL illuminated and remained on. Today I went to an Autozone and borrowed a code reader. It showed P0440, P0441. and P0446. I checked this forum and found out what the codes were as well as where to look for the problem. When I picked the car up last Friday after being serviced, I was given an inspection sheet indicating that the air filter was OK. The meant that the tech must have checked the air filter. Using the information obtained from this forum, I was able to locate a tube was not attached to its fitting on the air filter housing. I reattached the tube and reset the MIL. The light is off and all is well.
The dealership always sends a letter after the service, explaining that their desire is to deliver "excellent service," and if it was not excellent, they would like to know about it. I called and spoke to an "assistant service manager." He had some difficulty understanding how an oil change could cause the MIL to illuminate, but I was able to explain how it may have happened. He didn't seem too concerned, but I hope that he will mention the complaint to the technician, so it will not happen again. I certainly hope that the tube was unintentionaly left off, and this was not a method of increasing business by causing other problems. Many thanks to all who posted on this forum; I'm sure that I saved a bundle of money by fixing the problem myself!
Its probably the hose attached at the air filter box as someone else suggested. The guys at the quick lube places knock it off when they check your air filter.
One reason I never go to Quick lube joints. They are NOT mechanics. I hope yu know this! They ARE grease monkeys, that only know what a filter, oil and grease look like.( when yu are not looking they will never even grease your ball joints if so equipped.)
The Lube shop owners prep them to always check filters so they can sell yu ill fitting junk filters at premium prices!!
(The basic Lube they offer is Recycled oil and yu get crap filters that turn your oil BLACK before 3k miles. They under fill or over fill the crankcase 50% of the time!)
What good is that??
They know this and tell yu to get your next change in 3k miles for this reason . More money for them.
Many people don't get it! Ignorance is "Bliss", I guess.
DIY and never experience this again.
I understand most people can't DIY, but don't cut corners and trust your vehicle to a "Speedy lube joint! Go to a dealer or regular shop at least. So a mechanic can do the job.
Biggest scam going. I know so many people who come to me complaining about this and that happened at the Quick lube joints.
Even Dry crankcases leaving the lube shops and engines seizing up.
Quick lube joints are for people driving other peoples cars, taxis etc. Fleet cars, rentals and hoopty $50 train/commuter cars. Not for quality vehicles that are expected to give trouble free reliability for 200k miles or more.(Toyotas)
Many thanks for the response. I popped the hood and, sure enough, there was an unnattached vaccum hose. I reattached it, put the old original equipment gas cap back on and sailed through emissions without a problem. I wonder how much the dealer would have charged for this 5 minute repair?
Also, FYI from what I've seen in these forums there are two ways to reset the OBD. First disconnect the battery, pulling the negative cable won't effect the radio and other settings. The second is to pull the 20 amp fuse from the underhood fuse box for about 20 seconds. I didn't want to fool around so I did both. One or both worked because the check engine light was out and the emissions test center didn't pick any codes.
THANKS AGAIN!
I had an unattached vaccum hose also, so it turned out to be an easy fix. Thanks for all the great information! It is greatly appreciated!
I wanted to add my thanks for the postings on the cause of these codes. My CEL came on after an oil change. I was told to replace the gas cap but my problem was the disconnected hose from the air filter assembly. Apparently it is a know problem with the Highlander. I think I am going to replace the clamp, the OEM spring clamp is not very strong.
Let me also add my thanks, as about fifty miles after a "Quick Lube" oil change, my '03 Highlander CEL came on. An independent shop found code P0442, and said it could be many things, and too expensive to search for, so just let it go and see if it comes on again. It did come on again, and since it was due for the state emissions test, I Google searched, and found this forum. I remembered that my "Quick Lube" tech had held up my clean air filter and said "this needs changing." I told him "no", and he put it back. The filter box cover can not be removed with out first removing the small 1/4 inch black rubber hose from the back of the top section of the box. I doubt that it slips off by itself, as it has a spring clamp that holds it tight. So much for the "Quick Lube" places. I will never go back. This forum has saved me a lot of money and hassle. Thanks.
Flunked Emissions; DTC P0440, 41 & 46
