GM: TunerCat OBD2 Tuner


TunerCat OBD2 Tuner is a software package that allows tuning of 96-current GM vehicles.  For some early 96-97 vehicles, it is often the only solution. TunerCat OBD2 Tuner must be purchased with our RoadRunner hardware (either with a complete RoadRunner ECM or just a RoadRunner Guts kit)  due to licensing restrictions.  TunerCat OBD2 Tuner also has an optional reflash cable accessory and software (“WinFLASH”) that allows vehicles to be flash programmed over the OBD2 port.  Existing users of TunerCat OBD2 software can use a RoadRunner ECM with the RTOBD2 upgrade.  This upgrade is only available to existing users of the TunerCat software.

The software supports real time tuning with the RoadRunner on supported vehicles, reading and flashing over the OBD2 port. THERE IS NO BUILT-IN DATALOGGING APPLICATION. You must have a third party logger or scan-tool in order to have an effective tuning combination.  MX Scan used to work with older versions of the TunerCat reflash cable but it is NOT reported to work with current cables.

TunerCat OBD2 Tuner is licensed on a per-VDF (Vehicle Definition File) basis.  You can purchase each VDF individually or as a package including a group (LS1, All) of definitions and hardware together at a discount.  Each VDF generally covers multiple vehicles that use similar engine controllers.  Once you have purchased a VDF, you may tune as many vehicles of that type as you like – there is no per-VIN licensing.


Installation Tips and Troubleshooting

TunerCat OBD2 tuner relies on the same FTDI drivers that we use for the rest of our products.  If you suspect you have driver issues, please consult the USB Driver Troubleshooting Guide.

TunerCat OBD2 Tuner is not the most modern piece of software.  In fact, if you want the software to run properly we highly recommend that you use Windows XP as this is the only operating system that has consistent behavior without a fuss.  TunerCat OBD2 Tuner has been tested to run successfully inside a VMWare Virtual Machine running XP and can be made to run stable in this configuration.

If you cannot figure out a way to use Windows XP and are going to try to use TunerCat OBD2 tuner under Windows Vista, Win7 and Win8/8.1, follow these steps:

  1. If you’ve already run the installers, first uninstall the program.
  2. In order for the programs to install correctly the installation program must be run in Compatibility mode. Before running the setup program right click on it. Select Properties from the list and then click the Compatibility tab. From there, pick the default (Windows XP SP2), click on the ‘Apply’ button and then click on the ‘OK’ button.
  3. Now double click on the setup program to install the program and follow the on-screen instruction to complete the installation.
  4. After completing the installation you’ll also need to set the OBDII RT Tuner program itself to run in compatibility mode. To do so, right click on the OBDII RT Tuner icon on the Desktop, Select ‘Properties’ from the pop-up menu and then click the ‘Compatibility’ tab. On the Compatibility screen click on the ‘Run the program in compatibility mode, select the default Windows XP SP2, check the ‘Run as administrator’ box, click on the ‘Apply’ button and then click on the ‘OK’ button. Then repeat this process for the WinFlash OBDII program.


Vehicle Support

The latest list of supported vehicles can always be found here: TunerCat ODB2 VDF files

As of the time of writing (3-26-2012), the following vehicles are supported:

Vehicle Definition
File P/N

Supported Vehicles



1996 – 97 Vortec Trucks (4.3L, 5.0L,
5.7L, 7.4L)


1998 – 00 Vortec Trucks (4.3L, 5.0L,
5.7L, 7.4L)


1999 –
00 Medium Duty Trucks (7.4L MFI Gas)


2001 –
02 LS1 Trucks (4.3L, 4.8L, 5.3L, 6.0L, 8.1L)


2003 –
05 LS1 Trucks (4.3L, 4.8L, 5.3L, 6.0L, 8.1L)


– 07* LS1 Trucks (4.3L, 4.8L, 5.3L, 6.0L, 8.1L)

(*only 2007 trucks with old style
PCM are supported)


– 05 L6 4.2L Trailblazer, Envoy, Bravada


– 08 V8 Trucks & SUVs (CAN Bus E38 ECM)


– 12 V8 Trucks & SUVs (CAN Bus E38 ECM except 2011-12 L96 6.0L
Heavy Duty Trucks)


– 12 V6 4.3L Trucks & SUVs (CAN Bus E37 ECM)


2008 – 2009 Cadillac SRX 4.6L

2008 – 2012 Chevy Colorado 2.9L,
3.7L and 5.3L

2008 – 2009 Chevy Trailblazer, SS
4.2L, 5.3L and 6.0L

2008 – 2012 GMC Canyon 2.9L, 3.7L
and 5.3L

2008 – 2009 GMC Envoy 4.2L, 5.3L

2008 – 2010 Hummer H3, H3T 3.7L and 5.3L

V8 Cars

1996 –
97 LT1 Corvette, Camaro, Firebird, Impala

OBD2_09 1997
– 98 LS1 Corvette, Camaro, Firebird

– 01 LS1 Corvette, Camaro, Firebird

1999 – 2001 Holden


2002 –
03 LS1 Corvette, Camaro, Firebird


2002 –
2004 Holden


LS1 Corvette

OBD2_12 2004
OBD2_13 2004 – 05 Cadillac CTS-V


– 12 V8 Camaro / 2009 – 2011 Corvette (except 2011 ZR1)

OBD2_55 2006 – 08 Corvette
OBD2_56 2008 – 09 Pontiac G8 V8
V6 Cars
OBD2_15 1996 Camaro/Firebird
OBD2_16 1997 Camaro/Firebird
OBD2_17 1998 – 1999 Camaro/Firebird
OBD2_18 2000 – 2002 Camaro/Firebird
OBD2_23 1996 V6
Chevy*/Buick/Pontiac* 3.1, 3.4, 3.8L
OBD2_24 1997 V6
Chevy*/Buick/Pontiac* 3.1, 3.4, 3.8L
OBD2_25 1998 – 1999 V6
Chevy*/Buick/Pontiac* 3.1, 3.4, 3.8L
OBD2_26 2000 – 2001 V6
Chevy*/Buick/Pontiac* 3.1, 3.4, 3.8L
OBD2_27 2002 – 2003 V6
Chevy*/Buick/Pontiac* 3.1, 3.4, 3.8L
OBD2_28 2004 – 2005 V6
Chevy/Buick/Pontiac* 3.1, 3.4, 3.8L
(*2004/05 Grand Prix

OBD2_60 2007 – 2012 T42 Transmission
Controller – 4 speed Automatic
OBD2_61 2007 – 2012 T43 Transmission
Controller – 6 speed Automatic