Well on my non-hybrid denali it's as easy as pulling the fuse ... I know cause I did it after my retrofit cause I didn't want my hid low beams being on all the time. No loss of any function resulted ... and keep in mind the signals are even more interrelated in the Yukons because of the H13 setup which draws DRL as a low voltage signal from the high beam.

I was surprised that it was that simple myself.

 

You can turn them off manually until you can find a solution.
Once I can read my VCM, I will see if that is an option.

 

I am very interested in the ability to reprogram the ecm. For about 5 years I tuned GM fuel injection systems (everything from 80's TBI/TPI up to early LSx) and was a member of SAE. I helped a friend of mine get into the business and he ended up becoming an employee of HPTuners. Let me try and use that connection to get things rolling.
I'd really like to reprogram some of the shift points but just a little, firm up a tad or short shift the 1-2 because of how I drive. Right now the programming/tuning is balanced with priority given to emissions, then cafe (mileage), then durability for the WARRANTY period (not longer), and lastly performance/comfort. They do a phenomenal job getting it close to perfect but it isn't perfect for my drives and style. I will only do my tuning after the warranty has expired but when I do it'll be my hobby to get these beasts running better.

 

Jprevost, the 2 Mode is pretty complex. It doesn't shift like a normal step gear transmission. I had posted some links previous to public patents on the system. If you worked the older GM systems of TBI through simultaneous double fire and then into sequential injections then you are probably pretty good with speed density using MAP, throttle position, temperatures, etc to "tune" the engine.

Well this baby treats the engine as just a torque source. The hybrid is the master controller. The engine, transmission, and electric motors all follow hybrid commands.

So to change shifting will require extensive knowledge of the physics and limitations of the 2 Mode and how any change to one point can effect the engine, both electric motors, and HV battery.

 

Hillbilly, it is complex but that's what I like. The older systems were not very complex, they were just limited by the users time to reverse engineer the code so that you could manipulate the data, even then there were compromises that actually made things MORE complicated than the new stuff. For example, the 7747 and 8746 ecm's didn't have the space available to create a full volumetric efficiency lookup table, instead it had a smaller table and then an "adder" that was a simple scalar. They even had a logarithmic scale that was course by 200rpm at low revs and over 1200rpms at the top, rather complex.
With regards to the transmission, it still had gears and shift points because it has planetary gear systems, nothing variable about it. The variability in the name EVT has to do with the torque from the electric motors, not the 4 gear ratios. I think it's only 4 gears because it only has 4 wet clutches, hmm, I don't want to think about this lol. 3 gears sets, 4 clutches, you figure it out
I have a 10 mile commute and I think it would be wonderful if there were a way to manipulate and tweak anything. Speed limiters are of little interest but it would be amazing if I could add a button to KEEP the engine running, maybe there is code in there to do this? Often engineers will keep their diagnostic code in the computers because it is easier to disable with a flipped bit than it is to have multiple computers, might find some golden nuggets if we dig deep enough. Of course I have to remind everybody that this is for off-road use as it is illegal to tamper with emissions control devices!

 

Put it in M and the engine will stay on. Or trick the hood switch. As for nuggets, knowing where to dig is step 1.

 

Thanks, this is very interesting! I noticed another really cool feature today when I turned the heat on... when you leave it on auto and make a call using bluetooth the blower motors turn down. That's some smart engineering and means there is a lot of integration
I would really like to change the default hybrid screen in my nav. How about showing electric motor speeds, power output, etc. instead of the soccer mom invisible truck!
Where do I find more of these tricks Hillbilly?

 

For what it's worth, here is the GM TSB regarding aftermarket additions/tuning and warranties:

Identifying Non-GM (Aftermarket) Engine and Transmission Calibrations for V8 Gas Engines Using
Tech 2® or Global Diagnostic System (GDS)
TECHNICAL SERVICE BULLETIN
Reference Number(s): 09-06-04-026C, Date of Issue: August 13, 2010
Superceded Bulletin(s): 09-06-04-026B, Date of Issue: April 7, 2010
Related Ref Number(s): 09-06-04-026, 09-06-04-026A, 09-06-04-026B, 09-06-04-026C
ARTICLE BEGINNING
SERVICE INFORMATION
General Motors is identifying an increasing number of engine, transmission and catalytic converter part failures that
are the result of non-GM (aftermarket) engine and transmission control calibrations being used.
When alteration to the GM-released engine or transmission control calibrations occurs, it subjects powertrain and
driveline components (engine, transmission, transfer case, driveshaft and rear axle) to stresses that were not tested by
General Motors. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions
performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions
to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM
(aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed.
Warranty coverage is based on the equipment and calibrations that were released on the vehicle at time of sale, or
subsequently updated by GM. That's because GM testing and validation matches the calibration to a host of criteria
that is essential to assure reliability, durability and emissions performance over the life of the warranty coverage and
beyond. Stresses resulting from calibrations different from those tested and released by GM can damage or weaken
components, leading to poor performance and or shortened life.
Additionally, non-GM (aftermarket) issued engine control modifications often do not meet the same emissions
performance standards as GM issued calibrations. Depending on state statutes, individuals who install engine control
module calibrations that put the vehicle outside the parameters of emissions certification standards may be subject to
fines and/or penalties.
This bulletin outlines a procedure to identify the presence of non-GM (aftermarket) calibrations. GM recommends
performing this check whenever a hard part failure is seen on internal engine or transmission components, or before an
engine assembly or transmission assembly is being replaced under warranty. It is also recommended that the engine
calibration verification procedure be performed whenever diagnostics indicate that catalytic converter replacement is
indicated.
The PQC has a process to confirm the ECM/PCM calibration is GM issued. The PQC will require a picture of the
engine calibration verification screen, as outlined in this bulletin, before authorizing any V8 gas powered engine
replacement.
If a non-GM calibration is found and verification has taken place through GM, the remaining powertrain and driveline
warranty will be blocked and notated in GMVIS and the dealership will be notified. This block prevents any
UNAUTHORIZED warranty claim submission.
Affected
Model(s):
2006-2011 GM Passenger Cars and Light Duty Trucks (Excluding Saab 9-7X); 2006-2009 HUMMER
H2; 2006-2010 HUMMER H3; Equipped with V8 Gas Powered Engines Only
Attention: This bulletin applies to V8 gas powered engines ONLY. For Duramax™ diesel powered engines, refer
to the latest version of Corporate Bulletin Number 08-06-04-006G.
Supercedes: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number
09-06-04-026A (Section 06 - Engine/Propulsion System).
Identifying Non-GM (Aftermarket) Engine and Transmission Calibrations for V8 Gas Engines Using Tech ... Page 1 of 4

1. Connect the Tech 2® to the vehicle.
2. Go to: Diagnostics and build the vehicle.
3. Select: Powertrain.
4. Select: Engine.
5. *Select: Engine Control Module or PCM.
6. *Select: Module ID Information or I/M Information System if the Module ID Information selection is not
available.
7. *If "I/M information System" was selected, it may be necessary to select "Vehicle Information" in order to
display the calibration information.
8. If the CVN information is displayed as "N/A", it will be necessary to contact the TCSC (1-800-828-6860
English or 1-800-503-3222 French) to obtain the CVN information.
Fig. 1: Tech 2® Screen
Courtesy of GENERAL MOTORS CORP.
9. Take a CLEAR digital picture of the Tech 2® Vehicle Information screen showing the engine Calibration IDs
and Verification Numbers as shown above. Retain the printout information and the Tech 2® screen photograph
with the repair order.
10. E-mail a copy of the picture to tacsnapshot@gm.com. In the subject line of the e-mail include the phrase "V8
Cal" as well as the complete VIN and Dealer BAC. In the body of the e-mail, include the VIN, mileage, R.O.
number and BAC. Include a brief description of the customer concern and cause of the concern.
11. Allow two hours for the PQC to verify the calibrations and set up the case details.
12. If the PQC determines that the calibrations ARE aftermarket calibrations, DO NOT contact GM Technical
Assistance to discuss warranty concerns on the aftermarket calibrations. ALL questions and concerns about
warranty should be directed to the dealers Fixed Operations Manager (FOM), (Warranty Manager (WM) in
Canada).
13. You may call the PQC two hours after submitting the e-mail for authorization to replace the assembly. This will
provide them time to receive, review and set up a case on the request. Please be prepared to provide all the usual
documentation that is normally required when requesting an assembly authorization from the PQC.
TECH 2® DISPLAYING ALL ZEROES FOR THE VERIFICATION NUMBERS ON
THE CALIBRATION ID AND VERIFICATION NUMBER SCREEN
Fig. 2: Tech 2® Display
Courtesy of GENERAL MOTORS CORP.
If the Tech 2® that you are using displays all zeroes for the Verification Numbers as shown, then perform the
following steps:
1. Update the Tech 2® with the latest software from TIS2WEB.
2. Turn OFF the ignition for 90 seconds.
3. Connect the Tech 2® to the vehicle.
4. Turn ON the ignition, and build the vehicle. Observe the Tech 2® Calibration ID and Verification Number
screen for proper operation.
NOTE: All pictures must be sent as a .jpg file.
NOTE: The dealer will receive an e-mail reply after the calibrations have been validated.
The e-mail reply will advise the dealer if the calibrations are OEM.
Identifying Non-GM (Aftermarket) Engine and Transmission Calibrations for V8 Gas Engines Using Tech ... Page 2 of 4

5. If the Tech 2® screen still does not display properly, then turn OFF the ignition for 90 seconds again. Turn ON
the ignition and observe the same screen for proper operation.
RETRIEVING CALIBRATIONS FROM A GLOBAL A VEHICLE
This information applies to the 2010 Camaro and is typical of the procedure that will be used on Global A vehicles.
1. Turn OFF the ignition.
2. Connect the MDI to the Data Link Connector (DLC) of the vehicle.
3. Connect the MDI to a PC or laptop that has been downloaded with the GDS application from TIS2WEB.
4. Click: On the GDS icon on the PC.
5. The Login Page will appear.
6. Select: A User.
7. The ID Screen will appear.
8. Select: The serial number of the MDI being used.
9. Select: Connect.
10. Verify that the system status is ready by observing for a flashing PC light icon on the MDI.
11. Select: Make, Model and Model Year, in order to build the vehicle.
12. Click: Upload VIN, to allow the VIN to be reported to the PC.
13. At: The Verification step, turn ON the ignition, with the engine OFF.
14. Select: Next Action.
15. The Home Page will appear.
16. Select: Next.
17. The Diagnostic Screen will appear.
18. Select: Engine ID, if prompted.
19. Select: Module Diagnostics.
20. Select: ECM.
21. Select: ID Information.
22. The Diagnostics page will appear.
Fig. 3: Typical View of GDS Calibration History Screen
Courtesy of GENERAL MOTORS CORP.
23. Select: Calibration History from the drop down menu in order to display the following items on the screen:
NOTE: Use the USB port to make the following MDI connection:
NOTE: At least one Diagnostic Package must be installed on the PC to perform
diagnostics.
If GDS was just installed, select: Add New Diagnostic Package and then select: a
Diagnostic Package to download.
NOTE: Due to vehicle build, software and RPO variations, GDS may ask for additional
information in Step 18.
Identifying Non-GM (Aftermarket) Engine and Transmission Calibrations for V8 Gas Engines Using Tech ... Page 3 of 4

􀁺 Calibration History Buffer
􀁺 Number of Calibration History Events Stored
􀁺 Calibration Part Number History
􀁺 Calibration Verification Number History
24. Select: Screenshot.
25. Name and save the file in an appropriate folder.
26. Select : Print, and retain a copy of the screenshot with the repair order.
27. E-mail a copy of the screenshot to tacsnapshot@gm.com. In the subject line of the e-mail include the phrase "V8
Cal" as well as the complete VIN and Dealer BAC. In the body of the e-mail, include the VIN, mileage, R.O.
number and BAC. Include a brief description of the customer concern and cause of the concern.
28. Allow two hours for the PQC to verify the calibrations and set up the case details.
29. If the PQC determines that the calibrations ARE aftermarket calibrations, DO NOT contact GM Technical
Assistance to discuss warranty concerns on the aftermarket calibrations. ALL questions and concerns about
warranty should be directed to the dealers Fixed Operations Manager (FOM), (Warranty Manager (WM) in
Canada).
30. You may call the PQC two hours after submitting the e-mail for authorization to replace the assembly. This will
provide them time to receive, review and set up a case on the request. Please be prepared to provide all the usual
documentation that is normally required when requesting an assembly authorization from the PQC.
WARRANTY INFORMATION
􀁺 The Dealership Service Management must be involved in any situation that would justify the use of labor
operation Z1111.
􀁺 Notify the Fixed Operations Manager (FOM) (Warranty Manager (WM) in Canada) of the situation.
􀁺 All claims will have to be routed to the FOM (WM in Canada) for approval.
􀁺 Please refer to Corporate Bulletin Number 09-00-89-016, Labor Operation Z1111 - Suspected Tampering or
Vehicle Modifications for important information.
For vehicles repaired under warranty, use:
Warranty Information
© 2008 Mitchell Repair Information Co., LLC.
NOTE: GDS is capable of displaying up to 10 Calibration History events.
NOTE: All pictures must be sent as a .jpg file.
NOTE: The dealer will receive an e-mail reply after the calibrations have been validated.
The e-mail reply will advise the dealer if the calibrations are OEM.
Labor Operation Description Labor Time
Z1111 Suspected Tampering or Vehicle Modifications 0.2 hr
Identifying Non-GM (Aftermarket) Engine and Transmission Calibrations for V8 Gas Engines Using Tech ... Page 4 of 4