So here I would like to share my experience disabling F55 and reflashing DBS using GM Tech2 scan tool
GM TECH2 Features:
1) GM software in the Tech 2 Flash means the most comprehensive diagnostic software available for late model GM vehicles.
2) Support for on-board diagnostics on all GM systems 1992 thru current year.
3) Removable hardware modules provide insurance against scan tool obsolescence.
4) Large, easy-to-read backlit screen.
5) RS232 & RS485 ports provide the avenue to connect future devices to your Tech 2 Flash.
6) Ability to capture stored DTCs, Freeze Frame, and Failure Record for later review.
7) Ability to view the status of vehicle diagnostic tests as they run.
8) Bi-directional The authentic GM 1992-current year software will provide full bi-directional control when performing power train, chassis, and body diagnostics.
GM Tech 2 Specifications
1) Microprocessor: 32 bit,16 MHz
2) Memory: 32 MB flash type II PCMCIA. Type III slot available for future expansion.
3) Communications: Integral RS232 communication port.
4) Screen: 3.8.8 backlit monochrome with full graphics capability: 320,40 pixels. Displays up to 9 vehicle parameters at once .Download Tech2 Brochure (5.2 Mb)
An industry change in protocol from OBD II to Controller Area Network (CAN) has begun. In order to perform diagnostics on a vehicle that uses the CAN interface; You will need the Tech 2 Flash and a CAN diagnostic interface module. The module connects between the Tech 2 Flashs diagnostic link cable and the OBD adapter. Once the module is connected, it can be used on all GM vehicle applications,even those vehicles using other platforms such as OBD I and OBD II.
Disclaimer: Please strictly follow the steps in case anything goes wrong. The F55 disabling and DBS reflashing are on your own risk.
First I had the tech do the DBS reflash for me in about 10 min. My tune was NOT affected and the car started and ran normally.
I then had him disable the F55 suspension. Again, my tune was NOT affected and the car started and ran normally.
It is also worth noting that HP Tuners can NOT make changes to the BCM.
If you are looking to disable your F55 using the TECH2 scanner:
1. Hook up Tech 2, turn car ON, make sure module in the rear is PLUGGED IN. Do Not unplug the rear module.
2. Go to diagnostics — Body — BCM — BCM Special functions — BCM Setup.
3. Delete the F45 option ( F55 did not appear on the menu screen on the Tech 2, use F45)
4. Save new configuration.
5. Do not turn car off, do not remove Tech 2, go to the module in the rear of the car, unplug the grey connector( the widest one) leave the center plug in and the smaller black plug in.
6. Turn off car leave Tech 2 plugged in.
7. Remove remaining plugs from module in the rear of car.
8. Turn car on to verify the “Max speed 80 mph” is gone.
9. Unplug Tech2 and put tools away.
Then you have to follow the bouncing ball of checking off RPO Codes. When you get to F55 set it to disabled.