I wouldn't do that given the complexity of electronic modules an data bus communication networks on this vehicle . Disconnecting batteries can cause modules to go to sleep an not wake back up . The ignition switch is an input to the BCM - body control module , the BCM turns on relays powering up systems on the vehicle .
The BCM executes the high power mode by grounding the controlled power relay coil control circuit of the CONTROLLED POWER relay whenever the BCM is awake. This circuit also is grounded for 15 minutes after you turn the ignition switch to the LOCK position in order to obtain the RAP function. After 15 minutes elapse, the BCM enter a sleepstate and transitions to the low power mode. The components under controlled power then receive any necessary voltage from the battery positive voltage circuit of the BCM. If the BCM is in the low power mode, and the BCM detects that the current exceeds approximately 2 amperes, the BCM wakes up and re-enters the high power mode. If the vehicle remains inactive with the ignition in the LOCK position and without any BCM wake-ups for a period of 3 days, the BCM deactivates the low power mode. The following components are under controlled power: There are probably DTC'S - diagnostic trouble codes stored in the BCM . A simple code reader can not read these , an has nothing to do with the check engine light . Battery Disconnect or Replacement Problems
You may have been lucky so far disconnecting the battery .