Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Newb needs help 2012 GMC Canyon.

General Tuning Discussion

Forum Posts



Tech Articles

Discuss all things tuning in this section. News, products, problems and results. 

= Resolved threads


Thought I'd try popping my tuner cherry on my 2012 GMC Canyon LH9 5.3L w/VVT

I'm gathering data on this thing and I'm not sure if I'm doing something wrong, if I need to do some repairs, or if the factory tune is just really screwed up.

I bought this truck new so one owner and only me and the dealership has ever mechanically touched it. It has always had some drivability (shifting) issues when running it hard but has been a great truck for 6 years.

HP tuners scan data seems crazy. Fuel never moves off stoich unless WOT (which is factory set at 87% Throttle). Timing is all over the place (10 to 55deg advance) in the scan and it registers knock every time I get in the throttle.

I'll attach my last scan if someone might have time to look at it. Thanks!

Hmmm. I keep getting "Unhallowed file upload..." even though it says .hpl files are allowed.

You'd be surprised how odd some factory calibrations seem when we're looking at them from a performance standpoint. I'd say that almost all of the GM stock calibrations I've seen result in some knock from mild to terrible. It's also not uncommon for the PCM to have some serious delays before switching to PE in order to aid economy and emissions. Fortunately that doesn't mean we need to leave it like that.

I'll get our developer to look into the file type however in the mean time you can zip the file and upload it.

Trying the zip file...

I'm trying desperately to apply what I'm learning here so I really appreciate the help!

I've included the factory pre load along with my current tune after deleting the rear o2's and installing a wide band. I've also been messing around trying to disable a rev limiter that was capping me out at around 4400 RPM while doing a third gear pull (think I solved this in the speedo section of the tune under limit by fuel, speed limiter). I'm also trying to figure out how to lock 3rd gear for the pull. Vehicle controls in the scanner don't seem to do it. I actually took the car to a Dyno a couple days ago to get a baseline before tuning and they couldn't figure out why it was rev limited or why third wont lock. Best I can do so far is keep it from downshifting but it still goes to fourth at the top end.

Data is NOT consistent across the logs as I've added more channels the more I progress though the courses.

My wide band had a loose wire the last few logs so that's why you see it drop out.

Its also very important to note that I may not know what I'm doing!


Attached Files

I don't have much to offer on the transmission. I did pull up your log and it looks normal for a completely stock car. However if you want to understand the fueling better, you need to log the modeled catalyst temperatures such as "Modeled EGT at Bank 1 Catalyst" and "Catalyst temp B1". In VCM Editor go to Fuel-->COT,Lean Cruise-->CAT Over temp protection. Also, keep in mind that the parameters ending in [SAE] are likely going to be slower and blockier as they are meant for a generic scan tool, which typically gets lower priority on the CAN bus. So if possible choose a similar parameter name that doesn't end in [SAE].

US market cars are constrained by the federal Lean Best Torque regulation. The target AFR has to be stoichiometric, and if not, enrichment has to be lean best torque (typically mid 12's AFR on E0/E10 fuel) + ~3% enrichment is all that's allowed, unless it is required to protect emissions hardware such as the catalyst (or turbo). The EPA actually audits fuel maps (not as much back in 2011, but especially now) and drives cars around with on-road emission equipment to make sure your CO emission isn't too high in the real world resulting in a VW like situation. The other factor is, if the catalyst deteriorates too quickly, it will throw a catalyst efficiency code or fail EPA surveillence testing (they test the cars after 1 and 4 years in service). Then they get big fines. If you don't care about all that you can turn off the catalyst temperature protection, the cold engine spark retard to heat up the cat, all that stuff that is for emissions and not for fuel economy or power.

For the knock, your engine is running regular fuel right? So 87 US octane (about 92 RON). So it's going to knock a little more, because nobody wants to pay for anything more expensive than regular. As long as the occasional knock retard is reasonable (and ~5 degrees is considered reasonable) they don't really care, and it doesn't hurt anything. The tune is meant to be sort of lowest common denominator, because as you know GM sells a gazillion of those 5.3 engines and they all have basically the same tune. Also, look at the VVT angle as well, as that plays into spark timing.

I found "Catalyst Temp B1S1 & B2S1" and added both but could not find "Modelled EGT at Bank X Catalyst". I checked in the cat overtemp protection is enabled with the max enrichment of 1.33.

I'll have to go over all the sae log channels, if I remember right, every time I added one the software asks you if "you know what you're doing" and seems to suggest that you should be using a generic sensor. I figured I don't know what I'm doing so I just went with its recommendations!

The EPA stuff you mention make sense now. As a newb looking at the data I collected, it just seems strange that it stayed on stoichiometric for so much of the operating range. I guess that's why most tuning shops and tuners I have watched focus mainly on the wot/eq tables.

Yes, my pickup has seen mostly 87 octane all her life. I imagine I'll have to start running premium after I get the cam installed and definitely after adding forced induction. I will start paying attention to the VVT channels as well and see if can make sense of it!

It seems my truck may be running as gm intended. Thank you so much for your reply and and if there is anything else you think of might help me id gladly receive it!

I did finally figure out the 2 problems the dyno shop was having issues with. Transmission > General > Cmd Gear Control Limits > Max RPM and Max Speed were kicking HP Tuners vehicle control off allowing 3rd gear lock to come off at 62mph and again at 5500rpm. Adjusting those limits in the tune now allows HP Tuners control to keep a gear locked. Also Speedo > Limiter > Limit By Fuel was preventing the truck from going faster than 98mph so the truck just quit on the dyno at about 4400rpm. After adjusting i can full pull to redline!

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?