Monitor Description

The ECM receives a frequency signal (IWPI) from the electric water pump assembly and calculates the speed of the electric water pump assembly. As the frequency signal (IWPI) is 4 Hz when the electric water pump assembly is stopped to enable the ECM to detect an open or short in the signal line, the electric water pump assembly speed will be displayed as approximately 160 rpm even when the pump is stopped. If the electric water pump assembly speed is calculated to be less than 10 rpm, the ECM judges that there is an open or short in the IWPI circuit and stores this DTC.