Description & Operation: Notes

The first step in diagnosing any driveability concern is verifying the customer's complaint with a test drive under the conditions the concern reportedly occurred. Before entering self-diagnostics, perform a careful and complete visual inspection. Most transmission control concerns result from mechanical breakdowns or poor electrical connections.

The 4F27E automatic transaxle is electronically controlled by the 104-pin EEC-V Powertrain Control Module (PCM). The PCM also controls the engine management system. The PCM evaluates incoming signals from individual sensors and actuates solenoid valves located in transaxle valve body assembly for gear shifts and torque converter clutch application. Transaxle self-diagnostics can be performed through the Data Link Connector (DLC) using New Generation Star (NGS) tester, FDS2000, Worldwide Diagnostic System (WDS) or equivalent scan tool. The DLC is located under left side of instrument panel. The PCM is located under passenger side kick panel. See Fig 1 .

The 4F27E has Electronic Synchronous Shift Control (ESSC) which guarantees smooth shifting over the life of the transaxle. The ESSC feature monitors shift operations and adapts to wear in shift elements. If the PCM detects a deviation from stored values for shift time and shift synchronization, fluid pressure build-up or reduction is adapted accordingly. This is possible since shift elements in transaxle are actuated by PCM controlled modulating valves.