good question.....we has been experience before.it will be depend to the installer how there do it. but the correct way is arm the alarm then the engine still running after just switch off by the timer.
Want to ask about the GTT normal oil pressure?
1) when the car idle, it is below 4 or above 4?
2) when normal driving, it is below 4 or above 4?
3) when high rpm, it is above 4 or below 4?