This bulletin applies to 2014-2017 Mazda3 vehicles. If the vehicle stores DTC P2183:00 (ECT sensor No. 2 circuit range/performance problem), this is caused by the ECT sensor No. 2 located near the bottom of the radiator getting wet and water entering the part due to insufficient water resistance.

To correct this issue, the water resistance of the No. 2 sensor has been improved with an updated part. If the ECT sensor No. 2 internal circuit is corroded, the sensor output is far below the ECT sensor No. 1 output due to higher resistance. Determine if the No. 2 sensor is malfunctioning by comparing the two sensors’ outputs. The new and improved No. 2 sensor is available as P/N PE18-18-840. This also requires a new gasket P/N 9956-21-200.