Back Door Key Unlock Switch Circuit

Turn ignition off and disconnect ATS ECU connector. Lock back door with key. Ensure no continuity exists between ground and ATS ECU connector terminal A1 (Blue/White wire). If continuity is present, repair short in back door key unlock switch circuit. If continuity is not present, unlock back door with key and ensure continuity is present. If continuity is not present, repair open in back door key unlock switch circuit. If continuity is present, replace ATS ECU and retest.