Automatic Transmission - Diagnosis - 4L80-E: Description

The 4L80-E transaxle uses 2 electric shift solenoids to control transmission upshifts and downshifts. In addition, a force motor (solenoid) controls hydraulic line pressure, and a Torque Converter Clutch (TCC) solenoid controls TCC application. Solenoid is turned on and off by the Powertrain Control Module (PCM) or Transmission Control Module (TCM). The PCM/TCM has on-board self-diagnostics to help identify any parts or circuits that may need further testing.