Shift Solenoid: Description and Operation

PURPOSE
The [1][2]Torque Converter Clutch (TCC) system uses two Powertrain Control Module (PCM) controlled solenoids for engagement; a Pulse Width Modulated (PWM) solenoid valve, and an enable (apply) solenoid valve in the automatic transaxle to couple the engine flywheel to the input shaft of the transaxle through the torque converter. This reduces the slippage losses in the converter, increasing fuel economy.

OPERATION
The 4T6OE transaxles use two solenoids for shifting. The PCM uses inputs such as Throttle Position (TP) sensor, vehicle speed sensor, RPM and air flow to determine the correct shift points for the transaxle. Refer to Chart C-8B Shift Solenoid Functional Check (4T60E Transaxle. Under Computers and control System/System Diagnosis/Diagnostic Charts/C Charts. Testing and Inspection