Diagnosis & Overhaul - Km175, Km176 & Km177: Description
KM175, KM176 and KM177 are Electronically Controlled 4-Speed Automatic Transaxles (ELC-4A/T). KM175 and KM176 torque converters have lock-up clutch, controlled by electronic solenoid, to reduce or eliminate slippage at certain road speeds. KM177 does not have torque converter lock-up clutch. Transaxle shift points and hydraulic pressure to various friction elements are controlled by Transaxle Control Unit (TCU). TCU calculates proper shift points through input from various sensors and transmits electrical signal to appropriate Shift Control Solenoid Valve (SCSV). See Fig 1 . ELC-4A/T has a built-in fail-safe system to provide proper driveability in case of system malfunction. TCU has self-diagnostic capabilities.