Lincoln Navigator: Automatic Transmission - 10-Speed Automatic Transmission – 10R80 / Transmission Fluid Auxiliary Pump. Description and Operation

10-speed transmissions with the auto-start stop feature are equipped with a transmission fluid auxiliary pump. This electronic pump is turned on before an engine stop event; allowing the transmission to remain engaged during the stop event. This allows quick response on the engine restart because the transmission is already in gear. The transmission fluid auxiliary pump does not have sufficient flow to apply clutches, but can keep clutches on when the engine stops and the main hydraulic pump stops providing pressure.