Vehicle Platform & ECU Name DTC Troubleshooting Data Ver: 1 Date: 23/11/2022 Author: ERC Page 725 of 834 Copyright by TATA MOTORS Ltd. This document must not be used in any w ay, such as copying and redistributing to third parties, w ithout our consent P0641-89: Sensor Reference Voltage "A" Circuit/Open - Data Transfer Failure Overview: Code Cause Effect on Vehicle Fault Code: P0641-89 2. ECU internal failure 3. SPI Communication failure between Micro and Power supply during startup 4. SPI Communication failure after engine start. 4. CE lamp ON 5. Engine may not start 6. Reduced vehicle performance Lamp status: Checkpoints: 2. Check the Battery voltage at Ignition off (Nominal range - 11.5 V to 12.8 V) Trouble Shooting: Sr. No. Steps Specifications Step 1 Check for any VREF electrical fault - Step 2 If VREF electrical fault is present, address it first - Step 3 If the problem persists, replace the ECU - Verification condition: Drive the vehicle at city and highway condition for 20 mins. Component Details: The EMS ECU is an electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. It does this by reading values from a multitude of sensors within the engine bay, interacting with the other ECU on CAN (TCU, ABS/ESP, IPC, TOD, DCS, BCM etc.), interpreting the data using multidimensional performance maps (called lookup tables) and adjusting the engine actuators accordingly Check Engine Lamp on Malfunction Indicator Lamp off
RkJQdWJsaXNoZXIy MTIwNTUz