IMMO reset 2010 GMC Terrian

[realpoconojoe]

I replaced the PCM on a 2010 GMC Terrian and can't get it to do the security relearn. I even tried to do it with 2 different Autel scanners, neither would do it. I did not program this PCM since I couldn't find a proper (E39) core, so I bought one that was already programmed. If I disabled the VATS in the PCM, would this eliminate the need to do the relearn?

[TheMechanic]

It is most likely that you did not do a "write entire". You did a "write calibration". Otherwise if you want to keep VAT's you can do it non scan tool
KOEO for ten minutes. Lock light will turn off. Turn ignition off. Ignition back on for ten
Repeat this three times for a total off 30 minutes. Make sure the lock light goes out each 10 minute cycle. You can go longer but not shorter.
On the 4rth cycle on attempt to start. This will learn the key/cylinder.

[realpoconojoe]

I did try that several times, both trying it just turning it to ignition, also by turning it to the start position, and letting it return to ignition, since there are instructions, showing both methods. When you turn the ignition to the ignition position, the security light will go off in 4 seconds, so i feel the key is learned. I haven't flashed this ECM, I bought it already setup for the vehicle for the vender. Thanks for your help in this matter.