ccgoodwrench Posted February 26, 2007 Report Share Posted February 26, 2007 would like to know if their is any GM techs on this site, i've been having a prolbem with my evap system [about a year and a half] the truck will throw a code p0446 I just been clearing the code, i figured it was then vent solinoid so i put a new one on. so every time the evap system gets ready it throws the code. i finaly take it to the dealer, i wait 4 hours, and they say it was the vent solinod. i get in the truck and the light comes on again, they take the truck back in and after another 2 hours, they say it was a poor connecter at the vent solinod and the fuse was blown. i take the truck home and the readinees test is not complete since they cleared the codes. after a week of starting ( i think it takes like 40 warmup cycles to complete the tests) the light comes back on. so i really don't know what it is. i have also notice if i disconnect the vapor tube leading out of the vapor canister to the purge solinod it has gas dripping out of it. sorry for the long post but i need to get threw inspection. and is their a way of manualy completing the test without a scan tool Quote Link to comment Share on other sites More sharing options...
Holty Posted February 26, 2007 Report Share Posted February 26, 2007 http://www.silveradoss.com/forums/index.php?showtopic=29903 Quote Link to comment Share on other sites More sharing options...
drako Posted February 26, 2007 Report Share Posted February 26, 2007 ask tawws I believe he is a gmtech. He has been busy lately building his firebird (or transam?) anyways he checks in from time to time. Quote Link to comment Share on other sites More sharing options...
kelleyperformance Posted February 26, 2007 Report Share Posted February 26, 2007 (edited) i am, but its hard to tell ya without being able to diagnose it. the little bit of fuel in there is normal, but it sounds like something is obviously not working properly. it does kinda sound like the solenoid, or maybe somethings interfering with it via a cut in a wire or something. Edited February 26, 2007 by kelleyperformance (see edit history) Quote Link to comment Share on other sites More sharing options...
ccgoodwrench Posted February 26, 2007 Author Report Share Posted February 26, 2007 i have hp tuners and before i repaced the vent solinod i turned the solinod on and off and i can here it clicking, i really think that the cansiter is saturated with gas and is blocking the vapors from getting to the engine, so it is raising the fuel tank presure above a certain value and setting the code, somethig is letting the fuel into the canister. i supect the rollover protection valve, so i took it back to the dealer today and explained all this to the service manager and he says i don't know, they are getting on my last nerve. Quote Link to comment Share on other sites More sharing options...
CNE Posted February 26, 2007 Report Share Posted February 26, 2007 OK, hope this helps. First of all, if there is gas running out of the vent tube or canister, the canister has fuel in it and it shouldn't. This means it is saturated and needs to be replaced. There was a service bulletin back in 2004 for the P0446 that involved replacing the canister with a new design. The bulletin number is 03-06-04-037 and the canister part # is 15175906 and bracket # 15175907 is required to install. That is the first thing that needs to be done. Then there is a newer bulletin # 02-06-04-037B that addresses the cansiter vent valve being restricted, normally by dirt. I have replaced these before. What happens is it gets dirt in it and sticks open or closed. There is a kit in the bulletin, part # 19152345 which is a new valve and a remote filter assembly that is to eliminate dirt intrusion into the valve. This is the next thing that needs to be done. If they just replaced the vent valve with one just like what came off, it won't fix your problem. I would find out if they installed this kit or not. Hope this helps you out. Oh yeah, be prepared for attitude when you whip out some bulletin numbers and part numbers on them, we love it when a customer comes in and tells us what is wrong with their vehicle. LOL!! Quote Link to comment Share on other sites More sharing options...
ccgoodwrench Posted February 27, 2007 Author Report Share Posted February 27, 2007 thanks cnc, well i talk to the service manager and gave him the the service bullitin over the phone, and he said he will tell the tech, but i diidn't know about the one about the vent solinoid. it sounds like they are going to replace the canister with the same one.hope it works. it seems like i am the ony one with this prolbem. i just need to get threw inspection. and i will do the new canister and vent valve myself, i just took it to the dealer because it has the extened warranty. Quote Link to comment Share on other sites More sharing options...
ccgoodwrench Posted March 1, 2007 Author Report Share Posted March 1, 2007 i just got back from the dealer and they did not install the upgraded canister or the vent kit. i just don't get it i'm just trying to help them fix the prolbem. they have prolaby have wasted a full day of paying a tech and parts. i don't think i can go to a differnt stealership because i have already paid them $100.00 deductible the frist time i took it to them. so how can i get them to fix it right is their a print out of these service bullittens from gm and why don't they have them? oh and it already looks like gas dripping out of the vent line from the tank, maybe they didn't clean the lines out, so i think the code is going to come back after it completes the evap test Quote Link to comment Share on other sites More sharing options...
tawss04 Posted March 1, 2007 Report Share Posted March 1, 2007 ask tawws I believe he is a gmtech. He has been busy lately building his firebird (or transam?) anyways he checks in from time to time. Yea It's taking up soem of my time OK, hope this helps. First of all, if there is gas running out of the vent tube or canister, the canister has fuel in it and it shouldn't. This means it is saturated and needs to be replaced. There was a service bulletin back in 2004 for the P0446 that involved replacing the canister with a new design. The bulletin number is 03-06-04-037 and the canister part # is 15175906 and bracket # 15175907 is required to install. That is the first thing that needs to be done. Then there is a newer bulletin # 02-06-04-037B that addresses the cansiter vent valve being restricted, normally by dirt. I have replaced these before. What happens is it gets dirt in it and sticks open or closed. There is a kit in the bulletin, part # 19152345 which is a new valve and a remote filter assembly that is to eliminate dirt intrusion into the valve. This is the next thing that needs to be done. If they just replaced the vent valve with one just like what came off, it won't fix your problem. I would find out if they installed this kit or not. Hope this helps you out. Oh yeah, be prepared for attitude when you whip out some bulletin numbers and part numbers on them, we love it when a customer comes in and tells us what is wrong with their vehicle. LOL!! CNE is right, there should be no gas in that line. If the canister is fuel saturated it will feel heavy, with it off tilt it on end to see if any fuel drips out. What I have seen that causes this is people who top off their fuel tanks (this does not allow room for the fuel vapors) and stuck fuel tank vent valve (also caused by topping off) If the valve is stuck it allows raw fuel to enter the canister, thus cause it to clog up and the vent solenoid cant vent. This DTC is only ran above 1/4 tank and below 3/4 tank and must meet certain perameters to run not necc. 40 drive cycles. I'm leaning towards a stuck fuel tank vent valve (on top of the tank), but it is hard to diagnose a vehicle this way. Quote Link to comment Share on other sites More sharing options...
ccgoodwrench Posted March 1, 2007 Author Report Share Posted March 1, 2007 the last time i filled up the truck was about a week ago and i stop the fuel at about 7/8 and the vent valve you are talking about is that the rollover protection valve, i wiil prolably drop the tank if i get that code again and if i disable that code would it hurt anything the truck is garage kept and i never smell gas fumes in the garage thanks for taking time to help me out and hope you finish your firebird, i'm in the process of restoring a 70 chevelle been working on it for 12 years Quote Link to comment Share on other sites More sharing options...
bsteff Posted March 14, 2007 Report Share Posted March 14, 2007 ccgoodwrench, Have you resolved this issue? I think I am having the same problem right now. I get repeated P0446 codes and have just been clearing them via EFILive. I pulled the lines from the vent canister on my truck and saw no fuel. My truck died yesterday as I pulled into a parking lot and then idled very rough, so I am thinking I may have a vacuum leak somewhere. A few minutes later everything was back to normal though. BTW, do you have to drop the fuel tank to get at the vent solenoid? Quote Link to comment Share on other sites More sharing options...
ccgoodwrench Posted March 17, 2007 Author Report Share Posted March 17, 2007 ccgoodwrench, Have you resolved this issue? I think I am having the same problem right now. I get repeated P0446 codes and have just been clearing them via EFILive. I pulled the lines from the vent canister on my truck and saw no fuel. My truck died yesterday as I pulled into a parking lot and then idled very rough, so I am thinking I may have a vacuum leak somewhere. A few minutes later everything was back to normal though. BTW, do you have to drop the fuel tank to get at the vent solenoid? No i didn't drop the tank. It was real tough to get at the vent solenoid. And my e-vap rediness is still not complete after 2 weeks 254 miles. and about 30 inginition cycles Quote Link to comment Share on other sites More sharing options...
Holty Posted March 28, 2007 Report Share Posted March 28, 2007 keep us posted on this, im having a similair issue only i'm getting code P0455 which is a leak detected code though i found no leaks. Quote Link to comment Share on other sites More sharing options...
perk03z06 Posted March 28, 2007 Report Share Posted March 28, 2007 Here's some additional data on those trouble codes ... should be helpful ... EVAP CANISTER VENT BLOCKED P0446 This DTC will determine if a restriction is present in the vent solenoid, vent filter, vent hose or canister. MALFUNCTION CRITERIA AND THRESHOLD VALUE(S): EXCESS VACUUM TEST - STAGE I : Vent solenoid commanded OPEN Fuel Tank Vacuum ≥ 7 in. H2O for 2 seconds(monitored during initial purge ramp) OR EXCESS VACUUM TEST - STAGE II : Vent solenoid commanded OPEN during normal purge. Fuel Tank Vacuum ≥ 9.0 in. H2O for a time ≥ 23 seconds OR Vented Vacuum =< -2.5 in. H2O or Vented Vacuum => 5.0 in H20 For 3 seconds after cold-start key-up. SECONDARY PARAMETERS AND ENABLE CONDITIONS: TEST ENABLE : MAP DTC’s not active Volt-DTC’s not active TP Sensor DTC’s not active VS Sensor DTC’s not active Coolant Sensor DTC’s not active O2 Sensor DTC’s not active IAT Sensor DTC’s not active Fuel Level >15.0% but < 85.0% PLM > .89 System Voltage > 10V but < 18V COLD START TEST: ECT > 3.75°C but < 30° C IAT > 3.75°C but < 30° C Cold Temp Δ°C( ECT - IAT)<8.25°C if ECT > IAT BARO > 75.0 kPa WEAK VACUUM TEST -Stage I: Tank Vacuum ≥ 9 in. H2O within a value 40 integral seconds. TIME LENGTH AND FREQUENCY: EXCESS VACUUM TEST - STAGE II : 180 seconds Once per cold start at: • Power-up • Excess Vac. Stage I • Excess Vac. Stage II Test must complete within 360, 420 ,460, 525, or 600 seconds from when purge is enabled, Depending on application EVAP. Emission Control System Malfunction P0455 This DTC will detect a weak vacuum condition (large leak or restriction) in the EVAP. system. MALFUNCTION CRITERIA ANDTHRESHOLD VALUE(S): WEAK VACUUM TEST- STAGE I (Cold Test): Tank Vacuum < 11 in. H2O for a time greater than (30-80 integral seconds) depending on application. WEAK VACUUM TEST- STAGE II PASS CRITERIA(Warm Test): Stage I test failed previous trip and this trip. Passes if Tank Vac. > 11 in. H2O Note: Stage II can only report a pass SECONDARY PARAMETERS AND ENABLE CONDITIONS: TEST ENABLE : MAP DTC’s not active Volt-DTC’s not active TP Sensor DTC’s not active VS Sensor DTC’s not active O2 Sensor DTC’s not active Coolant Sensor DTC’s not active IAT Sensor DTC’s not active Fuel Level >15.0% but < 85.0% Power-up Vacuum Test Fail = False PLM > .89 System Voltage > 10V but < 18V COLD START TEST: ECT > 3.75°C but < 30° C IAT > 3.75°C but < 30° C Cold Temp Δ°C( ECT - IAT)<8.25°C if ECT > IAT BARO > 75.0 kPa TIME LENGTH AND FREQUENCY: WEAK VACUUM TEST- STAGE I (Cold Test): Fault present for an integral time ≥ 50, or 70sec. depending on application. Test must complete within 360, 420 ,460, 525, or 600 seconds from when purge is enabled, Depending on application WEAK VACUUM TEST- STAGE II (Warm Test): Fault present for a time ≥ 1400 sec. This is the maximum test time length. Once per cold start. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.