Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission System (UA80F) - Diagnostic Codes (2 Of 2) & Symptom Tests >> Automatic Transaxle System >> DTC U0100-87: Lost Communication with ECM/PCM "A" Missing Message [12/2019 - 10/2022] >> Typical Enabling Conditions