Automatic Transmission Fluid Cooler

WARNING: This page is about a different car, the 2018 Land Rover Discovery Sport. However, it is still accessible from the selected car via links, so may be relevant.

ITEM	DESCRIPTION
1	Hose connection - Engine coolant outlet
2	Hose connection - Engine coolant inlet
3	Automatic Transmission Fluid (ATF) cooler
4	Mounting bracket

The Automatic Transmission Fluid (ATF) cooler has three lugs which locate in corresponding lugs on the transmission main casing and secured with a screw. The ATF cooler is an aluminum housing comprising louvered fins and plates. The plates allow a cross-flow of ATF and engine coolant through the ATF cooler.

The plates are immersed in engine coolant from the ATF warming valve. This provides cooling of the ATF by the temperature differential between the ATF and the engine coolant.

Dependent on vehicle specifications the ATF warm up is provided by one of the following procedures:

The ATF cooler has an integral thermostatic valve, which controls the ATF flow through the cooler. Flow is restricted to improve ATF warm up time. The thermostatic valve is closed at temperatures of 78°C (172°F) and below, starts to open at temperatures of between 78 and 84°C (172 and 183°F). The thermostatic valve is fully open at temperatures of 96°C (204°F) and higher.

The finer control of the ATF warm up is provided by warming valves installed in the engine cooling system.