Abstract: An exhaust gas recirculation (EGR) heat exchange unit having an integrated heat exchange chamber and an integrated deaeration chamber is provided. A coolant opening and a deaeration opening each form direct passageways from the heat exchange chamber to the deaeration chamber. The heat exchange unit is configured to cool exhaust gas flowing through an exhaust gas transfer passage with coolant flowing within the heat exchange chamber and around the transfer passage. The heat exchange unit is configured to be mounted relative to an engine at an incline such that the deaeration opening is configured to evacuate gas from the heat exchange chamber to the deaeration chamber and the flow of coolant into the deaeration chamber through the coolant opening is configured to route the evacuated gas out of the deaeration chamber via the coolant outlet.

Abstract: An exhaust gas recirculation (EGR) heat exchange unit having an integrated heat exchange chamber and an integrated deaeration chamber is provided. A coolant opening and a deaeration opening each form direct passageways from the heat exchange chamber to the deaeration chamber. The heat exchange unit is configured to cool exhaust gas flowing through an exhaust gas transfer passage with coolant flowing within the heat exchange chamber and around the transfer passage. The heat exchange unit is configured to be mounted relative to an engine at an incline such that the deaeration opening is configured to evacuate gas from the heat exchange chamber to the deaeration chamber and the flow of coolant into the deaeration chamber through the coolant opening is configured to route the evacuated gas out of the deaeration chamber via the coolant outlet.

Abstract: A method is provided for testing a thermostat in a motor vehicle. The method includes an engine warm-up model and a thermostat diagnostic. The engine warm-up model predicts the temperature that the engine coolant temperature should be equal to at a given time after start-up. This is based on the engine coolant temperature at start-up, ambient air temperature, and how the vehicle is driven subsequent to start-up. This predicted engine coolant temperature is compared to the actual engine coolant temperature as read by an engine coolant temperature sensor. The error between the predicted engine coolant temperature and the actual engine coolant temperature is calculated and integrated over time. The thermostat diagnostic runs at a pre-selected temperature after start-up and compares the integrated error to a predetermined threshold value. Depending upon the results of the comparison, a pass, fail, or inconclusive condition is determined.

Abstract: A method is provided for testing a thermostat in a motor vehicle. The method includes an engine warm-up model and a thermostat diagnostic. The engine warm-up model predicts the temperature that the engine coolant temperature should be equal to at a given time after start-up. This is based on the engine coolant temperature at start-up, ambient air temperature, and how the vehicle is driven subsequent to start-up. This predicted engine coolant temperature is compared to the actual engine coolant temperature as read by an engine coolant temperature sensor. The error between the predicted engine coolant temperature and the actual engine coolant temperature is calculated and integrated over time. The thermostat diagnostic runs at a pre-selected temperature after start-up and compares the integrated error to a predetermined threshold value. Depending upon the results of the comparison, a pass, fail, or inconclusive condition is determined.

Abstract: A method is provided for diagnosing the rationality of a thermostat in a motor vehicle. The method includes an engine warm-up model and a thermostat diagnostic. The engine warm-up model predicts the temperature that the engine coolant temperature should be equal to at a given time after start-up. This is based on the engine coolant temperature at start-up, ambient air temperature, and how the vehicle is driven subsequent to start-up. This predicted engine coolant temperature is compared to the actual engine coolant temperature as read by an engine coolant temperature sensor. The error between the predicted engine coolant temperature and the actual engine coolant temperature is calculated and integrated over time. The thermostat diagnostic runs at a pre-selected time after start-up and compares the integrated error to a calibrated threshold value. Depending upon the results of the comparison, a pass, fail, or inconclusive condition is determined.