Inspection of ECM and Its Circuits: Notes
WARNING: This page is about a different car, the 2007 Suzuki SX4. However, it is still accessible from the selected car via links, so may be relevant.
Reference: PRECAUTIONS OF ECM CIRCUIT INSPECTION
ECM and its circuits can be checked by measuring voltage, pulse signal and resistance with special tool connected.
CAUTION:
ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM with ECM connectors disconnected from it.