G.M. has become more stringent with security in Global A modules in 2016 - 2017 vehicles. More modules in each vehicle are involved in the security communications. Used modules are not going to be able to be installed any more without serious repercussions.

Today, I installed a new EBCM in a 2016 Colorado because of communications problems. When you attempt to program this module, the first screen that opens is a security screen prompting you to enter the vehicle security password. Since the ECM, BCM, IPC, HVAC, SDM, and EBCM store the environment security password, this password must be entered before programming. Also, the VIN present in the new module must be 00000000000000000. Also, all other security involved modules must have the same VIN entered in memory.

The environment security password is a one time entry as is the VIN and cannot be changed or overwritten. If the incorrect password is entered and programming is attempted, the vehicle will no longer run and the module will now be useless and must be replaced.

The password cannot be read with GDS2 from any module and can only be accessed in two ways. If you are a dealer tech or have a friendly dealer to work with, the code may usually be read through a key code lookup screen and is referenced as the immobilizer code. The only other way is to call G.M. Techline and give them the VIN. For this, you need an account and many hoops to jump through before the password is given out.

With some modules such as the ECM, the code can be saved from the old module and transferred into the new unit during programming. However, if your old module will not communicate, the new module can only be properly programmed with a VCI number from Techline. Even with the proper password, programming takes many steps and is time consuming. Of course, since the procedure takes 4 times more than it used to, G.M. has cut the times back once again.

James from Florida