wjnjr

Is it possible to command the various OBD tests to run with a Tech2? I've read through the manual but haven't found anything.

digitaloutsider

Like force it to do the EGR and O2 sensor checks? Not that I'm aware of. Unless something major changed in the later PCMs, the car has to go through the various drive cycles to get them to complete. The Tech2 can check the readiness, but that's about all.

C5 Diag

What tests in particular are you trying to accomplish ??

wjnjr

For right now, the emissions tests and here's why: When I load a tune w/ HPTuners or erase a DTC with my OTC scanner, all the emission items reset to "not ready". After a few drive cycles most run, pass, and show "ready", but as we all know, the cat efficiency and evap tests can take a few more. Especially the evap test which seems to run only when it feels like it. Because I don't drive the car every day (or week) it can take a long time for all items to show "ready". I'm looking for a way to speed things up so I can pass my state emissions test next month. And yes, I've tried the official GM drive cycle over and over, it still took almost 500mi for the evap test to run.

Just got my clone Tech2 last week and in the process of learning to use it. It's amazing what it can do, but not everything is covered in the manual. Lots to learn.

jft69z

You can run an EVAP service bay test, used so techs can troubleshoot the system and test any repairs they made on it. Don't remember if it sets the monitor though.
Since you have HPTuners, just load a config with the o2 stuff turned to 'do not report' . Check your monitors, should be OK. After the emissions test, load the original tune back in if you want.

Not sure in your state, but in NY we're allowed 1 monitor to be not set, that's usually the EVAP. If your state wants them all set, then turn off the EVAP stuff too.

schpenxel

If you were to set all the emissions stuff DTC's to do not report, the readiness checks will happen instantly when you start the car and you'd be good to go, hypothetically.

wjnjr

I found the EVAP Service Bay Test buried deep in the Tech2's menus. However, It's not mentioned in either of the two Tech2 manuals I have. The factory service manual does mention it, but only gives a short description and says "connect the scan tool and follow instructions". It's a procedure similar to an abbreviated drive cycle - cold start, idle, drive, shut down. The idea is to get the evap I/M tests to run and the monitor to show "yes" a lot quicker than it normally does, which is exactly what I'm looking to do. I'll try it out in the next couple of days and see what happens.

jft69z

Quickest way is to turn the stuff off with HP Tuners.

digitaloutsider

The HO2S test is a lot easier to get to show Ready, especially in the cooler weather we're having now. The trick to that one is that the coolant temperature must be under X degrees to start the test. That got me over and over when I was trying to pass the emissions test in the August heat. Finally had to pull the car in the garage with the door to the house open and crank the AC overnight. In TX, on a 2001+ car, you can have one test in Not Ready status and still pass. Evap is a bitch and frankly I'm not sure to this day if it's ever shown Ready on that car.

schpenxel

This.

wjnjr

Thanks for the replies guys, but I've known that/done that for a while now. The question in the first post concerns using the Tech2 to command emissions I/m tests to run, not using HPTuners to defeat them.

What I've found out so far:
1) While the Tech2 can command the evap purge & vent solenoids, it's not the same as running the tests as far as I/M monitor readiness is concerned.
2) The service bay test is intended to get the evap I/M test to run quicker than it normally would, which is anything but quick.
.
As soon as it stops raining I'll give it a try.

wjnjr

Update: The service bay test works as advertised. Now all I/M monitors show "yes" which mean they will pass the TX State emissions inspection later this week. The whole process took less than an hour, much quicker than waiting forever for the EVAP test to run on it's own. It's interesting that while the service bay test specifically addresses the EVAP tests, the CAT I/M tests ran and passed too.

So my clone just earned it's keep. And to answer the original question: Yes, the Tech2 can command emissions I/M tests to run using the service bay test, which is not mentioned in the Tech2 manual, but is mentioned in the C6 shop manual. Big thanks to jft69z for pointing it out.

jft69z

Glad it worked out for you.

Keep in mind, that's a dealer/professional level tool that the techs would get a bunch of on the job training on its use and capabilities. Pretty sure when they made those manuals, they never figured China would mass produce these and everyone would own one. My Snap-On scan tools have manuals too, and there's not a bunch of deep level info there either, you have to use the tool and learn its capabilities (and limitations). After a couple of software updates on the tools, the manual is pretty much useless anyways after they add more features and updates.

Tom Gilfoy

Use the Tech 2 Paths info to get to what you want to do.

Tom Gilfoy

Look for tech 2 paths on the internet. It gives you a step by step list to follow to find what you want to do.