Hi there
This might be a bit complex but hope you can follow through this and answer some questions

Trying to help someone who has a repair shop that has a customer that built a Hummer with some changes
The vehicle's engine is not running well at all
This started with a PCM for a 2010 H3T alpha that would have had a 5.3L engine but instead the owner put in a 6.2 liter
He had at least 2 tuning vendors tune the PCM and the TM ( A4 tranny) and both could not figure out what the problems are

The engine is running way too lean, like +20-30 !

1. They are not sure if the MAF which is the card module type ( not a round type) that is in the airbridge, would there be a part # for MAF to then see if the same one was used for 2008 and 2010. Seems owner put some type of cold air box for airfilter and the vendor sold them the MAF in the Hummer now
2. Did a 2010 5.3L engine have flex fuel and/or DOD (4/8 cyl modes) ?
3. They then swapped the PCM for one that is for a 2008 H3T and attempted to tune out the problem as way lean conditions with no luck
4. Did a 2008 and 2010 uses the exact same MAF ?
5. If this builder did not install for flex fuel or DOD, does that effect the engine as long as they turned those functions off in the PCM tune ?
6 Being they are using 2 different PCMs, was there a functional difference in the 2008 and 2010 PCMs that would cause some issue as to
the MAF sensor used ?
7. Did either the 2008 or 2010 H3T have or support electric coolant fans ?
If not what is needed to allow using electric fans ?

8. Clearly has to be differences in the 2008 and 2010 PCMs and in fact the TCM for the A4 does work for one PCM but not the other
9. The first tuner locked the PCM with HPtuners, and refused to unlock it so Hummer owner had to get the PCMs he has now
and then a second tuner attempted to get the fuel trims correct and failed, so that is 2 tuners both failing

Any ideas on how to debug this ?

Thanks - JR

 

Also is there any TSBs related to lean conditions as to 2008-2010 for this H3 T ?

 

they need to transfer the maps from the 6.2 rom and compare it to the current tune. also they should have transferred the throttle body the pedal and the MAF sensor from the 6.2 donor. would probably went faster to use the 6.2 pcm and harness.

 

The 6.2 L engine came from a 2008 H2
Anyone know if that 6.2 L engine came with either flex fuel and/or DOD ?
I did a internet search and cannot find specs for that engine nor the 5.3 liter as if also had flex fuel and/or DOD

This build started as a 2008 H3T Alpha with a 5.3 L engine and builder had some tuner jock around with tune so I cannot
tell what the stock setting were and then used another PCM and had it flashed as a 2010 H3 and also tuned that so
I cannot do a compare of the 2 PCM calibrations as what stock setting were over what the 2 tuners did :-(

Thanks

 

they could probably contact HP Tuners and have them make a custom tune for you. tell them what you have parts wise and what was used in the swap.
they know there product better then anyone i would imagine.

 

The 08-09 & 2010 Alpha PCM can run the 6.2. It won't know the difference, the blocks are physically the same on the exterior. You will need to adjust the calibration for it to run correctly.

1. They are not sure if the MAF which is the card module type ( not a round type) that is in the airbridge, would there be a part # for MAF to then see if the same one was used for 2008 and 2010. Seems owner put some type of cold air box for airfilter and the vendor sold them the MAF in the Hummer now
---You can fix this by putting back in a stock MAF and you will certainly know the answer that we don't.

2. Did a 2010 5.3L engine have flex fuel and/or DOD (4/8 cyl modes) ?
---The 2010 H3T Alphas were all Flex Fuel capable, but did not have DOD. You can find this by searching the specs of the engine designation, which I believe is an LH9.

3. They then swapped the PCM for one that is for a 2008 H3T and attempted to tune out the problem as way lean conditions with no luck
---They did not make a 2008 H3T. Did you replace your O2 sensors?

4. Did a 2008 and 2010 uses the exact same MAF ?
--- I'm sure an '08 and '10 Alpha uses the same MAF, but the best way to find out on your 2010 would be to call the parts department at your local dealership and give them your VIN while asking this question.

5. If this builder did not install for flex fuel or DOD, does that effect the engine as long as they turned those functions off in the PCM tune ?
--- If you only use gasoline, I wouldn't imagine ethanol being an issue. If the engine they used had DOD, then they should have deleted the DOD with a delete kit.

6 Being they are using 2 different PCMs, was there a functional difference in the 2008 and 2010 PCMs that would cause some issue as to
the MAF sensor used ?
--- This is a good question for your tuner.

7. Did either the 2008 or 2010 H3T have or support electric coolant fans ?
If not what is needed to allow using electric fans ?
--- The E67 computer will support electric fans. You will have to have a competent tuner to enable these features for you if you are adding electric fans. You can also buy a Supermodulation Deluxe V8 fan kit that uses a temp sensor installed in the coolant hose without altering your tune file.

8. Clearly has to be differences in the 2008 and 2010 PCMs and in fact the TCM for the A4 does work for one PCM but not the other
--- There very well could be. the 2010 Alpha models were the only ones with the Flex Fuel capability. The 08-09 LH8 Alphas did not have this feature stock, so you will have to see if the 2010 Alpha ECM is the same as the E67 or not.

9. The first tuner locked the PCM with HPtuners, and refused to unlock it so Hummer owner had to get the PCMs he has now
and then a second tuner attempted to get the fuel trims correct and failed, so that is 2 tuners both failing
---It is common for tuners to lock their files. This helps prevent other calibrators from stealing or adjust their files and reselling them or using them as base files. I am not surprised that he did not want to unlock it.


Sounds like you guys may need to transfer the vehicle to another shop that does both tuning and vehicle diagnosing. I would check engine timing & the O2's.

 

2008-2009 Hummer H3/H3T Alpha used the LH8 engine.
2010 Hummer H3/H3T Alpha used the LH9 engine. This basically the LH8 with flex fuel capability and VVT.
https://help.summitracing.com/app/an...lh8%2C-and-lh9

2008 Hummer H2 used the L92. It had VVT, but not AFM or flex fuel capability.
https://en.wikipedia.org/wiki/Hummer_H2
https://help.summitracing.com/app/an...4851/related/1

https://en.wikipedia.org/wiki/Genera...l-block_engine

 

Thanks for all those who have replied with their knowledge

I did research on all this mess and think I have most of the issues answered

The builder ( not the shop that is now trying to fix all the problems) got a chassis directly from GM
They then bought a 6.2L that was in a 2008 H3 and the wire loom
In the end the H3T Alpha ran very poorly as the builder used a tuner in another state using HPtuners and when that did not work the builder then went to another tuner in another state.
In the end builder ended up with 2 PCMs that were of a different model but both are E67s.
I do not know what the difference are and

Each had a GM PCM calibration
1 was for a 2010 H3 with a 5.3L engine and the other
PCM was GM calibration for a 2010 H3T Alpha also for a 5.3L engine

Even though the engine is from a 2008 H3 with a 6.2L engine so both tuners did not tune for this engine
Then to make it worse and why engine's fuel trims were so lean is after I found the hard engine specs for the 5.3 and 6.2

5.3L would have flex fuel, no DOD
6.2 would not have flex fuel or DOD

BUT the builder used parts from a 5.3 and that is what all missed in that the specs for 5.3L uses a 30 lb/hr fuel injectors and the
6.2L uses 37 lb/hr
The math for the 2 makes the 30s 20% smaller then what the 6.2 is supposed to be using

I send the shop working on this tunes for the PCM and TCM as builder also put in 4.56 rear end gear and without the correct tune changes
caused the A4 not to shift correctly
Shop is to test the PCM changes and see if the fuel trims look more normal

Then there was electric coolant fans issue
builder added those and some relays, I do not know how they are wired but do know when the shop turned a/c on the fans come on but shortly shut down
I had the shop send me a OBD-II scanner recording and had them include the A/C PIDs.
In analyzing that data I found the builder did not freon charge the A/C and had low pressure which would cause fans to be shut down

Remaning question you all might answer is what is needed IF the builder wired the fan relays to the correct pins of the PCM what then in tune is needed to make the PCM control the fans ?
What type fan logic is needed as shown below ?

Many thanks



PCM fan control

Compare of both PCMs

 

you might be able to use the settings from a 2009 escalade if you can get a hold of a file.

 

For those with the interest of this Hummer H3 Alpha

I had the shop the owner sent vehicle to use a good OBD-II scanner in record mode and then email to me to analyze
It was clear by the data that they used another PCM and did not bother to relearn the crank position sensor
nor the TPS (APP, drive by wire) and because of that there was a high amount of misfire even at idle and the TPS values all over the place
Once the shop did those relearns the engine got better
To make it worse whoever the tuner was had not done this so instead they were trying to tune the PCM calibration around the problem
and made the total PCM tune much worse

The PCM used and the GM calibration was for a 5.3L engine with flexfuel yet a 6.2L engine replaced that engine

Clearly the tuner did not know what he sells as his business and because of that this Hummer has sat parked for over 1 year

Working with the new shop and doing what I suggested they do I obtained a GM calibration and flashed that into the PCM and via the
testruns shop did with the scanner recording and sending those to me to analyze I custom tuned the PCM and the TCM for the A4 tranny

Where the other tune that vehicle would only put out about 260 flywheel HP and about the same for torque

Now with the tune I did the fuel trims are good, all misfire gone and flywheel numbers are in the 450ish for HP and Tq



Lots of misfire at idle and TPS not rezoned to PCM

How the engine functions after I tuned the calibration for the makeup of this 6.2L engine reported by a road testrun Will get better after few more drive cycles