Most Helpful, your time is appreciated.👍As i said earlier,i wish i had more experience of the Meriva B so not certain what opcom or tech 2 will do on it,certainly on cars like the Astra H etc as long as you have the security number you could re-set most modules with opcom or tech 2,once re-set they can then be programmed into a different car.
Looking on TIS for the Meriva it does say the BCM holds the immo function as well as the ECM,
also from what i see the immo module on the lock housing may be part of the immo chain or even a dumb unit (reader)but it doesn't hold the immo function.
Here's a c/p from TIS
Immobilizer System Component Programming
This procedure will learn the immobilizer function. Following program function will take more than 15 minutes.
If the battery voltage is low, charge the battery before programming the control module.
Note: Before programming the Immobilizer Function, the body control module (BCM) and/or the engine control module (ECM) must be programmed.
1. Connect a scan tool to the vehicle and access SPS. Refer to Service Programming System (SPS) .
2. Turn ON the ignition, with the engine OFF.
3. Ensure that all power consuming devices are turned OFF on the vehicle.
4. Select SPS application and follow the on-screen instructions.
5. Select Reprogram ECU.
6. Select the IMMO Immobilizer Learn function.
7. Select the program Immobilizer Function.
Note: If both control modules were replaced, new virgin keys are needed.
8. On the next screen select the appropriate control module or modules if both are replaced. If only one control module was replaced select Use Existing Transponder Keys.
If both control modules were replaced select Use New Transponder Keys.
9. Enter the security code and follow the on-screen instructions.
10. With Use Existing Transponder Keys: After approximately 11 min. and after turn OFF the ignition for 1 min. the screen will display "Programming Complete".
11. With Use New Transponder Keys: After approximately 11 min. and after turn OFF the ignition for 1 min. the first key is learned. The screen will display “Learn Additional Key?”.
Select YES until all existing vehicle keys are learned.
12. After programming all keys “Programming Complete” is displayed.
13. With a scan tool, clear any DTCs.