COMPUTER RESET????
January 20th, 2016, 11:54 PM
#12
Drive cycle
Ok have same problem the cold start with every thing on is no problem but I live 10 miles or so from the freeway and been following the gm drive cycle with air rear defogger high beams interior lights four ways radio plus in gear but back to getting to the freeway after warm up 2 1/2 minutes if you drive back streets there is no way legally to do the 55 or not touch the brakes but will it allow you to drive to the freeway without canceling the drive cycle.Never mind I know the answer to that been trying to get just my evap to complete and after warm up I drive to freeway and it never fails.It wont just let you drive to the freeway you have to start there cold then follow the rest of the drive cycle oh yea truckers really don't like it when you coast to 20 mph much less coast to a stop a Dyno would come in very handy to complete this test with out pissing off truckers and other drivers.But like I said if you cant start on the freeway you probable wont pass the obdII drive cycle been trying now for months didn't know after the cold start and warm up for 2 1/2 minutes in drive you needed to be on the freeway.Know were a guy can rent a dyno for 15 minutes but you have to have your car there first start in the morning if your to stand a chance in hell of completing the drive cycle.I really believe this test was meant to be performed by gm tech's in there shop on a dyno then it would pass the first 15 minutes or first try.But unless you live and park your gm on a race tract with a steep off ramp good luck to ya.
January 21st, 2016, 2:36 PM
#13
Computer reset
Ok my question is to some one that knows a lot about the drive cycle.I have been trying to reset the evap im's since thanksgiving the week end after.I did my intake manifold gaskets the lower and replaced the battery and the alternator.Ever since then I have been trying the gm drive cycle that don't say in gear with air and rear defogger and all electrical.The 2 1/2 minutes is nothing I will start doing it in gear but how do you keep it from failing when the freeway is 10 miles away and impossible to not touch the brake turn signal or keep it under 55mph until you reach it.Will it allow you to restart the freeway part of the test when you arrive there so you can have every thing off and go 55mph for three minutes then coast without touching the brake ? can you use the four ways or blinkers on the freeway part.Second part accelerate to 55-60 and hold for 5 minutes then coast to a stop that part might be tricky to find a exit going up hill from the freeway.To let you come to a complete stop.
June 2nd, 2017, 11:22 AM
#14
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Donesha88: you don;t want to try and clear your monitor on the freeway. you need to slow down to 20mph and the truckers don;t like that. I found a long little used road out in the Mojave desert I used. my problem was getting a cold start out there, I left my truck set for a couple of hours to cool off, then did the cold start thing. to be honest I still have some of the monitors cleared, but still have two that won.t, still working on it.
June 7th, 2017, 12:25 AM
#15
Like I said in my earlier post on the issue of evap not resetting as a mater of fact I made quite a few post as I figured it out for myself. First read all the post I put on this forum then go to U Tube and type in The Ultimate Automotive Leak Detector and you will see for yourself what I built to find leaks all over the automobile and many other applications but most importantly it helped me to reset my computer in moments once I new the problem.
June 7th, 2017, 12:37 AM
#16
I see your issue is different and if I was to guess I would say the computer is loosing power when you shut the truck off its like when you disconnect the battery you have to give it some time to reset all of the monitors and the evap is one of the worst. Use a Power Probe you can google it and it will be one of your most prized tools and it can help find out if power is continues when truck is turned off. And it may just be a loose connection but you will need a schematic and one of these tools to make the job much easier. Also do you live in Washington Everett to be exact. Or the computer could be losing its memory but as I said first thin I would check would be the power to the computer and you could do the same test disconnect the negative first then the positive from the battery then hook up in reverse positive first. And see if you get same results as shunting the truck off and if so wiggle the wires carefully don't break nothing or get the tester I mentioned and test to know for sure.
Last edited by johnnylovsey; June 7th, 2017 at 12:59 AM.
June 7th, 2017, 12:49 AM
#17
Yes I have a Tech II that reads most everything and its able to let you know if the evap has passed or what the reason it hasn't. It can also do a bay test that is it will make the computer run as if it is driving and it will complete the drive cycle for the evap in your garage. I built a tool that will test for leaks and that is one of the most common problems of not completing emission test. Go to U Tube and check out the tool I built for finding leaks such as one I had in my evap that wouldn't let my monitor complete until I found and fixed the problem.
Last edited by johnnylovsey; June 7th, 2017 at 1:02 AM.
December 18th, 2020, 10:59 PM
#19
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2003 Chevy Silverado
Its called an OBD II Drive Cycle. its not a matter of how many miles you drive, but like MDTAHOE stated, its a matter of accelerating and decelerating properly. The exact procedre is below
An OBD Drive Cycle:
After you've "fixed" an emissions problem on your OBDII-equipped vehicle, you should perform what's called an "OBDII drive cycle." The purpose of the OBDII drive cycle is to run all of the onboard diagnostics. The drive cycle shold be performed after you've erased any trouble codes from the PCM's memory, or after the battery has been disconnected. Running through the drive cycle sets all the system status "flags" so that subsequent faults can be detected.
The OBDII drive cycle begins with a cold start (coolant temperature below 122 degrees F and the coolant and air temperature sensors within 11 degrees of one another).
NOTE: The ignition key must not be on prior to the cold start otherwise the heated oxygen sensor diagnostic may not run.
An OBD Drive Cycle:
After you've "fixed" an emissions problem on your OBDII-equipped vehicle, you should perform what's called an "OBDII drive cycle." The purpose of the OBDII drive cycle is to run all of the onboard diagnostics. The drive cycle shold be performed after you've erased any trouble codes from the PCM's memory, or after the battery has been disconnected. Running through the drive cycle sets all the system status "flags" so that subsequent faults can be detected.
The OBDII drive cycle begins with a cold start (coolant temperature below 122 degrees F and the coolant and air temperature sensors within 11 degrees of one another).
NOTE: The ignition key must not be on prior to the cold start otherwise the heated oxygen sensor diagnostic may not run.
- As soon as the engine starts, idle the engine in drive for two and a half minutes with the A/C and rear defrost on. OBDII checks oxygen sensor heater circuits, air pump and EVAP purge.
- Turn the A/C and rear defrost off, and accelerate to 55 mph at half throttle. OBDII checks for ignition misfire, fuel trim and canister purge.
- Hold at a steady state speed of 55 mph for three minutes. OBDII monitors EGR, air pump, O2 sensors and canister purge.
- Decelerate (coast down) to 20 mph without braking or depressing the clutch. OBDII checks EGR and purge functions.
- Accelerate back to 55 to 60 mph at ¾ throttle. OBDII checks misfire, fuel trim and purge again.
- Hold at a steady speed of 55 to 60 mph for five minutes. OBDII monitors catalytic converter efficiency, misfire, EGR, fuel trim, oxygen sensors and purge functions.
- Decelerate (coast down) to a stop without braking. OBDII makes a final check of EGR and canister purge.[/ol]
- my truck won't pass smog. But there is no check engine light on. Do u have any idea what it could be pls helping
February 5th, 2021, 7:18 PM
#20
CF Beginner
Computers
Here Is My 2 Cents...After An Overheat Or An Electrical Repair, Everyone Goes Chasing After Various Sensor Issues..Which Are Later Pointed At The BCMs And PCMs...Sure...Pull Cables To Reset, Go On The Required Drive To Reprogram Them, Only To Get New Or Repeated Issues...I May Sound Crazy...In My Opinion...These Things Get Viruses .....GO BUY NEW COMPONENTS......Thanks