Recently GM has switched to a much more robust security seed/key system and the WinFlash OBDII program can no longer calculate the security key in real time. With this new system you will have to obtain a security key the first time you work on an ECM/TCM. Once you get the security key of the ECM/TCM you will be able to read and program this ECM/TCM as many times as needed. There is a $45.00 administrative fee for these special security keys. We will e-mail the security key back to you as soon as possible. We will typically respond the same business day or the next business day depending on what time of day we receive your order.

When purchasing a special security key please be sure to include the security seed for the ECM/TCM which is shown in the WinFlash OBDII program in the order notes or send a separate e-mail to us at tc@tunercat.com with this security seed or the vehicle information file generated by the WinFlash OBDII program. For more detailed information regarding the new security keys and how to work with them in the WinFlash OBDII program click here.