NEXON 3.0 EV DTC Troubleshooting Document for VCU Version: 2.0 Date: 22-Sep-2023 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. The pump contains a microcontroller, which decodes the input PWM signal, calculates corresponding set speed of the pump and controls the motor. The pulse-width modulated (PWM) signal is defined by VCU. The operating mode and the set speed of the motor represents frequency (fin) and Duty Cycle (DCin) of the signal. Figure 3 Electric coolant pump and its pin details Preliminary Checks: 1. Check for design intended LV Battery. Voltage should be in range of 8V – 14V 2. Check if coolant is present until prescribed level of coolant tank. 3. Check for any abnormalities such as damage/short circuit in wire harness and LV connectors Trouble Shooting: - Step Description Check point If Yes If No 1 Check whether the vehicle is in Ignition State, vehicle speed is 0 and LV battery voltage is >11 V. Using TML Diagnostic Service Tool give command to operate actuator: ‘Traction cooling pump PWM Duty cycle’ (DID No: 3439- Traction cooling pump PWM Duty cycle) at 50% dutycycle i.e. (0x32 hex) Confirm whether positive response is received. Go to step 2 Ensure the preconditions to be OK (Vehicle is in Ignition mode; vehicle speed is 0 and LV battery Voltage is >11 V) Check for the negative response ID and Go to step 1 2 Read the vehicle parameter - Traction cooling pump PWM Duty cycle (DID No: 3439) Check whether value is 50. Let the pump to run for 1 min and proceed to step 3 Go back to step 1
RkJQdWJsaXNoZXIy MTIwNTUz