johnnylovsey

I cant get my 2003 gm blazer 4.3 liter to reset the evap emission system I have a 3050B INNOVA code reader but all it will do is yellow light with no hard code no code at all I have put about 12 gm drive cycles on it still no code or explanation as to why it wont reset.Could use some help here been at it for a month and 1/2 and I don't know how many miles.But with out a code I don't know were to start.?

cleveland63b

is there a check engine light? you might need a different/better scanner

johnnylovsey

No check engine light no code in all three memories.A month or so ago did the lower intake gaskets because of a coolant leak. that's been solved but the evap purge control switch had a leak coming from below it so I replaced the O Ring and that solved the air hissing noise but one other thing same valve on dissemble for intake the white snap clip that holds it is supposed to release by squeezing both sides of the clip.But it didn't so I took a pic tool and probed it and broke a 1/4 of it but I thought it still snapped on was going out to hit the connection with some soapy water in a spray bottle to see if can find a leak in hose coming from the venture will throttle it up in case there is no suction at idle ? is soapy water best thing to use on that connection and do you think they sell those clips separate.

cleveland63b

guess i'm having a hard time understanding what you want reset if theres no light on?

johnnylovsey

Let me un,confuse you I think I just did it for myself.I have the INNOVA 3050 code reader and after I did my intake gaskets the evap system said incomplete with a yellow light on the tester meaning not emission ready.And it has stayed that way on the innova tester for a month now with out any codes. So I went to ORileys auto parts and used there bosh tester and it said emission ready no codes.But for some reason the INNOVA 3050 still reads evap incomplete I think the Inova is faulty.No Mil no codes I think I will buy the bash and stop worrying about passing the emission test by the way in Washington if one monitor is truly not ready will they let you pass if all the others supported are.And sorry for the confusion that INNOVA tester has had me thinking there was a problem for a month now.The makers of it said try removing the battery then try again did same results So there next attempt to save its reputation was to plug it in to another car and then go back to my blazer to see what it reads.Think I will just buy the bosh it says I am ready for the emission testing and by the way the 4.3 liter runs I have to agree.

johnnylovsey

I have gone thru so much money trying to get the evap IM to complete and like you said no code no light EPA says you can pass emissions without that IM complete if all others are.So for now will wait it out go pass emissions and wait to see if it resets on its own and if it don't then maybe its time to look into the PCM.

johnnylovsey

Bought a new code reader a Actron CP 9680 and guess what it reads Evap monitor not complete but a day after received it I got a code PO107 low input Map censor. So pulled it out to look at it grommet was torn at the bottom a little.So went to O Riley's bought one after doing the test for the map censor did a back probe on the harness with key on grey wire 5 volt then hooked up my hand vacuum pump and with the ignition on pump up at 5 hg at a time and the map censor dropped 1 volt for every 5 hg.Its bull crap they don't cell the grommet separate so you have to buy the hole new censor for $70.00 life time warranty.Even though the grommet was the only problem not the censor.

cleveland63b

unfortunately theres a lot of things like that now, only come as assemblies. Glad you got it figured out though.

johnnylovsey

Just curious what causes the evap system to show not complete with out any codes and the 4.3 runs awesome And if you try to do a drive cycle the warm up in gear is pretty straight forward start put in gear turn on air rear defroster and every thing in the car for 2 1/2 minutes.But if you live 10 miles away from the freeway and the next part of the test reads accelerate to 55 mph turn every thing off don't touch the brake,drive at 55 mph for 3 minutes coast down to 20 mph no brake no gears now getting to the freeway isn't so hard but according to the drive cycle you have to drive 55 mph not touch the brake or gears rite after the warm up so back street driving is out of the question.By now you should be on the freeway if you didn't get pulled over trying to make it to the freeway in the 3 minutes.Then the last part of the test isn't so hard if a trucker don't try to run you off the road during the 5 minute drive cycle 55 mph again then coast down to a stop here,s the part truckers and most drivers like very little as well.My question is if you cant use the brakes then you more then likely cant use the 4 ways or blinkers to let anyone know what your doing.So coming to a stop is a tough one unless rite at 5 minutes your able to locate a up hill off ramp.And keep from getting killed from angry drivers.Tell me if you will is there a easier way that don't cost a fortune.To complete a drive cycle if one had access to a dyno and a good scanner with live monitor reading because you could monitor when the temperature is low enough to start the test then on the dyno every thing is real easy sounding and a very good possibility of completion.

johnnylovsey

This new code reader has a evap test so it says haven't seen any results when using it.You pick it out of menu special functions click on it and it says please Waite connecting with car computer so then it finished that part it says to continue hit enter when you do it says command was sent so that's it not sure what it really does.It also has under same menu drive cycle and when you reset a code or the mil it resets all of the im,s and on the drive cycle they all flash until they complete and all do except the evap system been 2 month,s now have replaced a faulty vent valve a map sensor because the grommet was torn and replaced the O' ring on the evap purge valve but still no complete.Been trying to pass the gm drive cycle on google but its not even close well it is close but not complete compared to this one got from a gm tech.
Here, this tells you what is being tested at each step of the drive cycle. Note that Purge appears in 6 of the 8 steps. Better do them all.

I imagine a problem with anything within a step could prevent the entire step from completing.

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General Motors (specific) OBD II Drive Cycle
Performing a GM OBDII Driving cycle:
Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 122°F (50°C) and within 11°F (6°C) of the ambient air temperature at startup.
Do not leave the key in prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater,Passive Air, Purge "No Flow", Misfire, and - if closed loop is achieved- Fuel Trim.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 55 mph (88 km/hr) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 55 mph (88 km/hr) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 20 mph (32 km/hr). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 55-60 mph (88-96 km/hr). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 55 mph (88 km/hr) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.