Automatic Transmission/Transaxle: Description and Operation

Circuit Description
The Powertrain control module (PCM) provides precise gear shift timing and torque converter lock-up by controlling the operation of the automatic transaxle solenoid valves (low & reverse solenoid valve, damper clutch control solenoid valve, over-drive solenoid valve, 2nd solenoid valve and under-drive solenoid valve).

The PCM operates these solenoid valves based on input signals from the various sensors(for instance, Pulse Generator A and B). The transaxle control module has a built-in self diagnostic feature.