Code U3573 indicates a malfunction in the electrical circuit that controls the coolant mixing valve. This valve is responsible for regulating the flow of coolant between different cooling loops to optimize engine temperature and cabin heating.
The internal electric motor or solenoid within the mixing valve has suffered a mechanical or electrical failure.
Wires leading to the valve have become frayed, pinched, or shorted due to heat, vibration, or rodent damage.
Moisture and road salt have caused corrosion at the electrical connector, leading to high resistance or an open circuit.
The fuse protecting the mixing valve circuit has blown, cutting power to the actuator.
The engine control module has an internal failure preventing it from sending the correct signal to the valve.
Yes, if the coolant cannot be routed correctly, the engine may run too cold or too hot, which can impact fuel efficiency and emissions.
No. U3573 is typically caused by the valve itself or the wiring. Replacing the PCM is rarely the correct fix and should only be done after the actuator and wiring are proven functional.
Yes, if the valve fails in a position that restricts the flow of coolant to the radiator, it can lead to engine overheating.