cardiagn.com (a) Disconnect the G4 gateway ECU connector. (b) Measure the resistance of the wire harness side connector. Standard resistance: TESTER CONNECTION CONDITION SPECIFIED CONDITION G4-24 (GND) - Body ground Always Below 1 Ω (c) Measure the voltage of the wire harness side connector. Standard voltage: TESTER CONNECTION CONDITION SPECIFIED CONDITION G4-10 (BATT) - Body ground Always 10 to 14 V G4-2 (ACC) - Body ground Ignition switch ON 10 to 14 V G4-1 (IG) - Body ground Ignition switch ON 10 to 14 V REPAIR OR REPLACE HARNESS AND NG CONNECTOR REPLACE GATEWAY OK ECU NG REPAIR OR REPLACE HARNESS AND CONNECTOR OK REPLACE GATEWAY ECU