Torque Converter Clutch
See MISCELLANEOUS ECM CONTROLS .
See MISCELLANEOUS ECM CONTROLS .
The transmission/transaxle converter clutch eliminates power loss of torque converter stage when vehicle is in a cruise condition, allowing driver convenience of automatic transmission and fuel economy of a manual transmission. Fused battery ignition is supplied to converter solenoid through a brake switch.
On some models, 2nd, 3rd and 4th gear hydraulic apply switches (located within transmission) may also be in series with solenoid power or ground circuit. On other models, switch status may only be monitored by ECM, without sharing power or ground with converter solenoid. For wiring reference, see wiring schematics under MISCELLANEOUS ECM CONTROLS in I - SYS/COMP TESTS article in this section.
Converter clutch engages when vehicle is moving faster than a pre-calibrated speed, engine is at normal operating temperature, throttle position sensor output is not changing (indicating a steady road speed) and transmission 3rd gear or high gear switch (if equipped) and brake switch are closed.
When vehicle speed is great enough (about 20-45 MPH as indicated by the vehicle speed sensor), ECM energizes converter clutch solenoid mounted in transmission, allowing torque converter to directly connect engine to the transmission. When operating conditions indicate transmission should operate as normal, converter clutch solenoid is de-energized, allowing transmission to return to normal automatic operation. Since power for the converter solenoid is delivered through the brake switch, transmission also returns to normal automatic operation when brake pedal is depressed. To check function of converter clutch system, perform functional check of system. See MISCELLANEOUS ECM CONTROLS in I - SYS/COMP TESTS article in this section.