Abstract: Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned through each of an air-conditioning condenser, a charge air cooler (CAC), and a transmission oil cooler (TOC) of the coolant circuit to maintain an estimated transmission oil temperature (TOT) below a threshold. The TOT is estimated from a torque converter slip ratio.

Abstract: Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

Abstract: Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

Abstract: Methods and systems are provided for controlling coolant flow through parallel branches of a coolant circuit including an AC condenser and a charge air cooler. Flow is apportioned responsive to an AC head pressure and a CAC temperature to reduce parasitic losses and improve fuel economy. The flow is apportioned via adjustments to a coolant pump output and a proportioning valve.

Abstract: Methods are provided for engine coolant system diagnostics. In one example, engine coolant system malfunction is indicated based on an engine coolant temperature inference model, whereas in another example engine coolant system malfunction is indicated based on a time-based monitor, where the inference model is enabled at ambient temperatures above a predetermined threshold, and where the time-based monitor is enabled at ambient temperatures below the predetermined threshold. In this way, accurate engine coolant system diagnosis may be accomplished under ambient temperature conditions wherein the engine coolant temperature inference model may be compromised.

Abstract: A system and method for demonstrating or testing operation of on-board diagnostics in a vehicle include imitating performance degradation of a vehicle hardware component and/or associated vehicle system by dynamically modifying at least one control system parameter value associated with the hardware component in response to a request to demonstrate operation of a selected diagnostic function or a specified performance degradation. Embodiments modify at least one control system parameter value associated with the input/output signal of a sensor/actuator to imitate a specified performance degradation. The diagnostics independently monitor operation of various vehicle control systems and operate to detect the degraded performance without knowledge of, or distinguishing between, whether the performance degradation was caused by an actual hardware component, or by the requested modification to the control system parameter value(s) associated with a particular hardware component.