P0446 My Troubleshoting Continues... - Toyota Nation Forum : Toyota Car and Truck Forums

Shuichi · 01-16-2010, 04:56 PM

OK, here is just an update to the P0446 EVAP problem I have on my 99 CE. So far this is what I have done. Got code P0446, cleared it once. After 4 days and about 140 miles or so the code came back and I cleared it again. I used the service manual and checked the Canister Purge Valve located under the hood and the the EVAP Pressure Switching Valve located next to the charcoal canister. Both checked good. All the resistance checks were good and voltage checks from the PCM to the connectors were good. I even checked the valves with a 12 volt source to see if they opened and closed properly. Both worked fine. I checked the vacuum hoses located near both valves and around the canister and they all seamed fine. I also checked the fuel tank pressure sensor and got good voltage going to it from the PCM. Now heres my question. there a two ports on the fuel tank pressure sensor. Is air supposed to flow freely through both ports. When I tried to blow from on port to the other I got nothing. Is this how is supposed to work? I really would like to find out before I spend the cash on a new canister. Thanks

tomtom25 · 01-16-2010, 06:06 PM

With that code right there if i'm not mistaking there is a TSB out for that code for an updated PCM/ECM! I can double check for you to make shore but I think there is one. I work at a Toyota dealership an can look it up if you like! Did you buy that at a dealership? Sometimes they're covered under warranty but alot of the times it's only up to certain miles an months of ownership!

Shuichi · 01-18-2010, 12:42 AM

Yeah I researched the TSB for code P0446 and I think my VIN is to low of a number and doesnt apply. The last 6 numbers of my VIN is 181000. The TSB applies to cars that start with VIN 186337 and up. So Im guessing my car doesnt apply. Below is a link to the P0446 TSB and a copy of the Corolla FSM P0446 troubleshooting chart. http://www.justanswer.com/uploads/sk...3_99_rolla.pdf http://www.justanswer.com/uploads/sk...99_rolla_2.pdf

tomtom25 · 01-18-2010, 07:46 PM

It should apply to your vin cause I know when I'm lookin at them at the shop for vehicles it always applies to the vin numbers prior to the one stated so your's should be under it cause it falls before the one you posted. It wouldn't let me open the link to see for shore but just from previous experience with lookin at them that's how it normally is though. I work at a toyota dealership. Try the tsb an see if that fixes your problem i'm almost shore it will! Let me know if you try it or what or if ya want more looking into it!

Shuichi · 01-19-2010, 12:06 AM

Ok so I am a little confused. The TSB states starting VIN is 186337, my vin is 181000. Does the TSB mean all VINs 186337 and below or 186337 and up? Also. it applies to 96 months or 80,000 miles whichever comes first. The TSB came out in 1999, 96 months later would be 2007. Im still way under 80K so I think they will not honor the TSB because I ran out of time. I was thinking if it is an ECM and they do not replace mine for free can I just buy an updated one from a slavage yard and put it in? Do I need to program anything?

tomtom25 · 01-19-2010, 08:58 PM

The TSB should be for 186337 and below that meaning that starting from that vin number there they started puting the new ecm in. If you're still way under 80k then you should be ok but you're right though sometimes they don't want to honor it for some reason but as for the bying an updated one that's fine ya just have to get your vin programed to the new ecm. It's not hard to do an takes just a few minutes to do if ya got the software. The ECM's themselves aren't that hard to replace either. Sorry about the confusion man and I hope this helps ya alittle.

ryanschillinger · 02-09-2010, 12:37 AM

Does the TSB apply to Chevy Prizms as well?

liensalebuyer · 02-10-2010, 09:11 PM

Tomtom, where is the ECM? Right on top in the engine easy access? I got my 99 VE about sixteen months ago and it's at 85K right now. Changed both VSVs and box underneath with a used one, P446 is still on. I think this info might be the fix unless there is a leak in a hose.

liensalebuyer · 03-23-2010, 09:40 PM

finally put in a used ECM from ebay for my 99VE. Code is off, but I think it's off because my co worker disconnected the old ECM first. Funny thing is P0446 always came on after 20 minutes of driving after being turned off by the scanner. Two new VSV, now this used ECM, hope it's the trick. I just got a 92 Camry and 96 Corolla, so this 99 VE doesn't get driven too much, hopefully CEL stays off. Time to work on the others for oil leak and bad tranny.