NEXON 2.0 EV DTC Troubleshooting Document for VCU Version: 1.0 draft Date: 31-Jan-2022 Copyright © TATA MOTORS Ltd. This document must not be used in anyway, such as copying and redistributing to third parties, without the consent of author. Electric coolant pump and its pin details Pump can recognize stall or over-temperature if the printed circuit board (PCB) temperature exceeds TDeRated, the pump speed is limited to 60% of the maximum speed. There are 2 detection scenarios observed with over temperature which are discussed in detail below. The temperature is measured with a NTC resistor on the PCB within the pump. The temperature thresholds are Over-temperature derating (TDeRated) 137 °C Over-temperature shut down (TOverTemp) 145 °C Detection Scenario Reaction Diagnosis Overtemperature derating When the PCB temperature > 132 deg C for more than 20s, the pump will restart again according to the PWM input signal. No diagnosis will be sent to VCU. During overtemperature derating, the Lifebeat is still sent. Overtemperature shut down If the PCB temperature exceeds 145 deg C, over-temperature is detected and the pump is switched off immediately. When the PCB temperature < 140 deg C for more than 20s, the pump will restart again according to the PWM input signal. During active overtemperature shut down, a diagnosis will be sent Check Troubleshooting table for healing Restart attempts will take place after certain pause times as mentioned in Figure 12. Pause time between the restart attempts
RkJQdWJsaXNoZXIy MTIwNTUz