I am very sure I have #6 misfire and I will be replacing coil & wire (I am sure this is the cause).

Question: Should I be able to clear the code using my tech2 BEFORE I fix the problem?
The tool say's cannot clear code, try again.

Or: Do I HAVE TO fix the issue BEFORE I can clear it with tech2?

It seems to me I should be able to clear it and then have it reappear next drive cycle (if I don't fix it). But maybe that's not how it works.

Anyone know?

 

I don't have a Tech 2 but a high end Autel...What DTC are you trying to clear ??...the misfire ??...you usually are able to clear the "history " misfires. BTW, how do you know that the misfire is ignition related ??...did you check the fuel system (injector) or maybe do a compression test on #6 ??...99% of DIY'ers go for ignition first... these other things can cause a misfire too. You should be able to do a fuel injector balance test with the Tech 2 but you'll need a fuel pressure gauge to pulse the injector.

 

The wire was burnt up and hanging down near the oil pan, ya think?



My specific question has to do with clearing codes with t2.

Can you "CLEAR" it even if the fault was there last time the car ran.

Thanks.

Or not possible to clear until the car runs w/out fault?

 

 

With tech2 ignition is on acc, the tool menus through various parts of car

engine
body
etc. (I forget)

When a code is present a number 1 appears (so 0's are good)
Tool says "clear dtc's" you push yes & it "thinks/try's to clear" for a while.
Comes back either cleared or cannot clear. If not cleared Try again?
So you try a couple times and then post to the forum



The specific question (again), do you have to FIX the fault before you can clear it? It's yes or no.

I thought you could fix without clearing and then drive the car and make fault appear again, but it may be you cannot clear UNTIL fixed. I just don't know, learning the tool.

 

 

The documentation for a knock off is scarce so you have to learn on the job .... Froggy post a picture of the screen u are in as I dont think that is the screen to clear new codes . You might be looking at history codes

Dave

 

Thanks guys, will post tomorrow.

 

This


So what am I doing wrong to clear the code?

Broken tool?

 

Nope nothing wrong with the tool , fix the coil and then start the car , go thru everything you have done without the car running but this time have the car running .....

Then clear the DTC . Its not clearing because it's trying to check to see if the problem is gone , without the engine running it cannot complete the test so it fails ....nothing wrong with the tool

Plus you have to be in RUN mode not ACC .......hold the start button but don't press on the brake , your dash and gauges should power up . At this point you have everything booting up that is on the CANBUS ( the communications bus )

Now you cant start the car and do it as you still have a bad coil so it's just going to set the code again . Replace the coil , plug the Tech ll into the obd port , do not use the 12 volt power source , the obd port will supply your power , once started turn on the tech ll and go in and clear the code
If u still have a code for misfire check the plug . I just went through all of this with my neighbors 2013 chev truck except I did not buy a coil , I just swapped the coil and wire , the misfire was still popping the code and I could not clear . Pulled the plug and the tip was missing ... something that happens with our plugs also
let us know how it works out Froggy

Dave

 

I also forgot to ask u , is it check engine light on ? If not then it's not a hard code, it's just a history code ...

Dave

 

The check engine light has gone out.

I think I like the c5 code system better where a code was either "H" or "C". History or current.

 

Thanks, I had no information at all on any of this procedure. No instructions, learning the tool.

Did not know it would run off the obd2 port, did not know engine had to be running, The instructions I did get said put in ACC mode. I need a local (or online) class on tech2.



Should have coil monday.

Thanks for helping.

 

you bet
Dave

 

Froggy, Make life simple and go into Vehicle control systems menu, and pull up all the DTC for all the modules one shot. Not only can make sure that all the modules are showing up on the GM land bus to start with, but gives the number of each modules DTC as well

Also, either put the car into run mode/motor off with the battery on a 10 amp charger so you don't drain the battery, or just start the car and run the DTC's check.

Now with the full list of DTC, you can go thought the list module by module to see if the problem came up with that motor start up check for a specific DTC, or was an old code that did not come up with that start up instead.
Now you go through the DTC's per module to delete them out one at a time as desired.

So to short bus it, your not going to delete a code out from the ECM menu directly, since the ECM menu is really just for montoring only. Hence on the older vets like the say back to 2008, you use to get the pop up menu telling you such, but that pop up is missing for the 2013 menu isntead. Hence to program anything directly into the ECM, it has to be done through SPS to get control of the ECM for programing/change purposes.

Its the System Control Menu you want for the 2013, and again, its a hit miss with just being in ACC mode, instead of run mode with all the module awake, since the car will not do a initial start up check to see if the code is re-thrown that start up instead (hence trying to delete an ongoing problem until the problem has been really fixed).

Really, the only time you want to be in Acc mode, is when you doing the automated brake bleed, since you need the EBCM not doing it normal thing with the car in run mode monitoring. Hence in on- mode, and even with the motor off, the EBCM is going to heat time out the pump when you are cycling the ABS pump after about the first caliper since it monitoring the rest of the system as well.

And again, in run mode, motor off, get a 10 amp charger on the battery to keep the battery voltage above 13 volts. If you don't, you have a few mins until the battery voltage on the dash drops under 10 volts, and then your going to have a hand full of new loss communication DTC's as the module glitch from lack of voltage. Hence it the way I can tell if someone had to jump a car, since that low voltage module glitches when they tried to start the car with the battery to low on voltage, leaves behind a trail of U codes every time.

As for tech II classes, it not a one shot deal on the C6s' of how you get to different menus/functions. The 2005 has it's set of ways/menus to get to items, the 2006 through 2008 another set of ways, then 2010 to 2013 another set of ways as well. So it just a mater of knowing what your after, and depending on the year range, how you get to them in that years menu on the Tech II instead. So after a few different car years of using the tool, and knowing what you can and can't do with the tool, pretty easy to use it isntead. Really, when you go use GDS2 with it more straight forward approach, training is a lot simpler instead.

 

Dano is the man !

Dave

 

Obviously knows the tool.


Every thing I learn will be up on my channel for all to learn, Seems there is not much (to my surprise) on the tech2.

 

So before I replaced the coil




I tried using the tech2 to look at the/any misfire at #6. I found one live (engine running) screen that was supposed to track it & nothing appeared. I think AT IDLE the connection was sufficient. I really did not want to cruise the fwy at 80mph and try to balance the tool and read the screen.


Is that all there is on the tech2 for looking at ignition? One misfire screen? Humph. I'm not sure that's a wonderful tool as everyone says.

I can feel/hear a misfire and I can look/examine plugs/coils/wires.

What do you think? I know the tool has many other uses. But I thought it was a little more than that.

 

Froggy,
Unfortunately as far as misfires go that is the only data PID that a scan tool will show...whether it's a $20.00 code reader, your Tech 2 or a $10,000 Snap on Verus !!...your Tech 2 doesn't show misfire counters??...I'm surprised...does that thing show misfires under generic OBD2 mode 6 if the Tech 2 has it ??...my Autel MS906 shows misfire counters under OEM and Generic. There is a TON of info in a scan tool but few of the people I've given some help to on this Forum have one but have NO idea how to use it to interpret the data...if you are going to just read and clear DTC just take the damn car to Auto Zone. A scan tool can give you "direction" but will not tell you what part is bad. If I had a dollar for every O2 sensor I've seen changed on the Forum needlessly I'd be driving a Bugatti Veyron !!...was the O2 sensor wiring checked ??...probably not...I helped someone on the C5 Forum last month who replaced 2 MAF sensors and still had the DTC pop up...I said..."did you check the 3 MAF wires??...he said "no" so I showed him how to check it electrically and he found the 5 volt reference wire was chaffed through on one of his pulleys... you have to check it !!...BTW if you want a quick way to check for a misfire hold a dollar bill up to your exhaust pipe...if it gets sucked you have a misfire. Like I had previously said not all misfires (which gets it's info from the Crank Sensor) are "ignition" related...can also be a bad fuel injector or something mechanical...burnt valve or broken valve spring. Did you fix that misfire with the new coil ??

 

Coil tab looks to be burn up by either a bad spark plug wire, or the wrong lube used to install the spark plugs wire. If I was a betting man, would day to say that someone used lithium spray grease to lube the plug boots and connectors, isntead of dielectric grease, and was most of the problem of a bad connection between the coil and spark plug wire isntead.

As for coil, can not get a good look at the tab, but it looks to be saveable via just bead blasting the end tab in the socket to remove the layer of burnt up grease preventing a good connection instead.

As for the tech II, I use it more for getting to the BCM, EBCM, and other modules that standard type scanners can not get to, programming and SPS firmware flashing with TIS2000, and other type functions, than really data logging with it instead. Hence you can weed out a lot of electrical gremlins, buy going through all the modules to check working voltages of them. Hence problem in the module connector down line of the BCM, or it's ground points. Plus comes in handy when you have a problem with say one of the doors not opening and such, since you can unlock the door via the tool to see if the problem is the locking latch, or the pad/button/wiring to the BCM isntead.

You can live data log with the tool as your driving, but the hanging cords can be a problem with the tech II over in the drivers seat as your driving.
So for live data logging, I use a wifi Elm327 in the obd II port, and lap top running Scan master elm over in the passenger seat instead. Hence laptop has a larger screen, and can set up the data logging to what I need to look at while driving, so I can glance over to the large laptop screen to see if there is real time problems isntead.