Engine Warm-Up Mode The EAT ECU monitors the output from the transmission fluid temperature sensor in the transmission and also receives an ECT sensor signal from the ECM on the CAN. When the transmission fluid and/or the engine coolant temperature is less than CF, the EAT ECU initiates the shift maps used in sport mode, when driving after a cold start. The sport mode shift points raise the engine speed. This, in turn, promotes faster transmission fluid warm-up and also decreases the warm-up time for the catalytic converter to reach optimum temperature. The warm-up mode is terminated if the vehicle speed exceeds 37 mph (60 km/h), the transmission fluid or the engine coolant temperature exceeds CF) or a maximum time of 3 minutes is exceeded. HDC Mode The HDC mode assists the ABS ECU in controlling the downhill speed of the vehicle. When HDC is selected on, the EAT ECU selects the most appropriate gear for the descent, to maximise engine braking. Cruise Mode When cruise control is activated, the EAT ECU receives a cruise active message on the CAN. The EAT ECU activates a cruise control map which prevents locking and unlocking of the torque converter clutch and minimises up and downshifts. If cruise control is operative and the vehicle speed increases due to coasting downhill, the ECM can request a downshift via a CAN message if the vehicle speed exceeds the set cruise limit. Hill Mode Hill mode is initiated by the EAT ECU when high engine torque, high throttle angle and low engine speed is detected via ECM signals on the CAN. The EAT ECU defines this combination of signals to determine when the vehicle is travelling on a steep gradient. In hill mode the EAT ECU adopts one of three shift maps which hold the transmission in low gears throughout the ascent. The shift map chosen depends on the severity of the slope as determined from the engine signals. Hill mode can also be initiated when the vehicle is at very high altitudes.