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

Prepared by: Airbag COC Review Approved by: Sanjeev VM Page: 81 of 648 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. SRS / Airbag ECU AB12 DTC Troubleshooting Guide Version: 2.0 Date: 21-June-2021 U0401-81:- Invalid Data Received From ECM/PCM "A" - Invalid serial data received Overview:- ISO Code U0401-81 Customer Symptom N.A. Fault Effects (On Vehicle) No effect. Lamp Status (If Any) N.A. Fault Detection Condition Incorrect or implausible vehicle speed data received from ECM control module by RCM (SRS) ECU. Normal Operating Condition Error free communication between RCM and ECM Control Module. Probable Trouble Area Implausible vehicle speed data received from ECM ECU. Healing Condition Clearing of the functional failures in the ECM Module. Component Details:- (Refer Annexure 2 for Mounting Location of AB12 Airbag ECU) Airbag ECU: - It is fitted in the floor of central console in the car. The Airbag Electronic Control Unit (ECU) controls the deployment system to allow an appropriate igniting of the Airbags and belt pre-tensioners to restrain the driver and passengers. Preliminary Checks:- 1. Ensure the proper locking of Airbag ECU wiring harness connectors in the vehicle by the locking sound. 2. Check resistance between diagnostic CAN pin number 6 and 14 in OBD connector. It should be 120 ohm. 3. Check for short conditions between CAN_H-CAN_L, CAN_H-GND, CAN_L-GND, CAN_H-Vbat and CAN_LVbat. There should not be any short circuit conditions. 4. Check continuity between ECM CAN_H (pin no. 19) vehicle side connector to OBD connector CAN_H (pin no. 6) and CAN_L (pin no. 18) vehicle side connector to OBD connector CAN_L (pin no.14). 5. Read IVN DTCs in IPC in Ignition ON condition.