This article is just sharing real experience when use GM Tech2 Scanner . Hope this helps someone.
I decided to invest in some tools to diagnose my Opel. After a couple weeks of searching all over ebay, aliexpress and other online store, I finally found the cheapest one on obd2tool.com, they were very fast to respond and answer all of my questions. I exchanged emails with Customer service for about 3 days before I finally decided to purchase a GM Tech 2 clone here.
Below is the procedure, I search and learn from forum members:
1. Obtain all ECU pin codes especially second hand ECUs (immobilizer or engine). Scan old ECU to obtain VIN code and then obtain car passes to match.
2. Obtain all keys they will be required at end of procedure. SPS program new engine ECU with vehicle engine code and VIN number.
3. Configure engine ECU CAN configuration (Engine/ programming/ program CAN configuration)
Configure engine ECU variant configuration (Engine/ programming/ program variant configuration)
4. Reset engine ECU if second hand ECU use pin code from car pass (body/ immobilizer / additional functions/ reset engine ECU)
Reset immobilizer (body/ immobilizer/ additional functions/ reset immobilizer)
Reset BCM (body/ BCM/ additional functions /reset BCM)
Reset instrument cluster (body/ instrument/ additional functions/ reset instrument)
5. Program immobilizer function (engine and immobilizer): this will program everything together includes new keys. Have all keys programmed (body/ immobilizer/ programming/ program immobilizer function).
Check and clear all fault codes Engine immobilizer dash BCM ABS and gearbox. Road test and recheck it.
Great! I can see automotive diagnostic equipment GM Tech 2 replace a new engine ECU for Opel Corsa C successfully!