VEHICLE WITH AN EGR-COOLER AND ITS DIAGNOTIC

摘要

In a vehicle provided with an engine, an EGR cooler for cooling EGR gas recirculated from an exhaust channel of the engine to an intake channel thereof by using a coolant, an electric pump for supplying the coolant to the EGR cooler, and a gas temperature sensor for detecting the temperature of the EGR gas temperature at the downstream of the EGR cooler, an ECU acquires a first gas temperature in a normally stable state where the electric pump is rotating, thereafter performs a coolant amount suppressing process to suppress the rotational speed of the electric pump, acquires a second gas temperature in a suppressed stable state after a predefined time has elapsed from the start of the coolant amount suppressing process, and determines that the EGR cooler is abnormal if a difference between the first gas temperature and the second gas temperature is less than a threshold value.

主权项

1. A vehicle provided with an engine having a recirculation channel for recirculating a part of exhaust gas flowing in an exhaust channel to an intake channel, the vehicle comprising:
a cooler, in contact with the recirculation channel, configured to cool a recirculated gas in the recirculation channel by a coolant; an electric pump configured to supply the coolant to the cooler; a temperature sensor configured to detect a temperature of the recirculated gas in the recirculation channel at a downstream of the cooler; and an electronic control unit configured to determine whether or not an abnormality is present in the cooler, the electronic control unit being configured to acquire a first gas temperature detected by the temperature sensor when a rotational speed of the electric pump is a first rotational speed, the electronic control unit being configured to set the rotational speed of the electric pump to a second rotational speed smaller than the first rotational speed after acquiring the first gas temperature, and then acquire a second gas temperature detected by the temperature sensor, and the electronic control unit being configured to determine that the cooler is abnormal if a difference between the first gas temperature and the second gas temperature is less than a threshold value.