TIAGO TIGOR BSVI - SERVICE MANUAL - DTC 24-12-2021

TATA BSVI Gasoline Program – EMS ECU Bosch DTC Troubleshooting Service Manual Version: 1.2 Date: 18-12-2019 Prepared By: Sunita Mandlik Checked By: Yeshwant Jadhav Approved By: Satish Kumar Document Part No: 2921 02 xxx xxxx Page: 1064 of 1498 Copyright © TATA MOTORS Ltd. This document must not be used in any way, such as copying and redistributing to third parties, without the consent of author. U0001-88: Vehicle Communication Bus A-Bus Off Overview: ISO Code U0001-88 Customer Symptom All warning lamps will be ON, Vehicle will not Start. Fault Effects (On Vehicle) CAN communication in vehicle will be OFF. Lamp Status (If Any) CE Lamp ON after 1 drive cycle Fault Detection Condition 1. Short circuit between CAN_H(C1, 32)-CAN_L(C1,44); CAN_H(C1, 32)-GND(C1, 53 and 54); CAN_L(C1, 44) – Vbatt(C1, 55 and 56); CAN_L(C1, 44)-GND GND(C1, 53 and54) and/or CAN_H (C1, 32) – Vbatt (C1, 55 and 56). 1. Open circuit of CAN_H/ CAN_L/ both lines Normal Operating Condition ECM communicates properly with TML diagnostic Tool. Probable Trouble Area CAN_H and CAN_L wires Healing Condition 1. Removal of short circuit conditions mentioned above in the wiring harness or at ECU pin. 2. Reconnecting CAN_H/ CAN_L/ both lines Preliminary checks: 1. Check ECM is communicating with TML diagnostic DTC or not. 2. If not, check for short conditions between CAN_H-CAN_L, CAN_H-GND, CAN_L-GND, CAN_H-Vbatt and CAN_L-GND at ECM vehicle side wiring harness (pin details are provided with schematic in the document). There should not be any short Circuit conditions. 3. There should be continuity between vehicle side wiring harness with following pins. IPC CAN_H (pin. 6) to ECM CAN_H(C1, 32) and IPC CAN_L (pin. 5) to ECM CAN_L(C1, 44) Continuity should be there. 4. Read IVN DTCs in ECM after IGN ON condition with TML diagnostic tool.