HEXA

ELECTRICAL 154 IVN DIAGNOSTIC TROUBLE CODES: Three types of IVN DTCs are present.  Message Time-Out Error  Missing message Error  Communication Bus-Off error ( One DTC against itself ) Exception:  ABS/ESP does not log missing message DTCs.  FATC ECU only receives data so do not log communication bus-off DTC. Its log only missing message & message timeout DTCs.  ABS logs CAN communication bus open error. IVN FAILURES: Following are the list of failures of the CAN network  Short circuit failures in the harness 1. CAN_H and CAN_L short circuit 2. CAN_H and GND short circuit 3. CAN_L and GND short circuit 4. CAN_H and Vbatt short circuit 5. CAN_L and Vbatt short circuit  Open circuit failures in the harness / Connector 1. Open circuit in the main CAN bus 2. Loose connection near ECU connector due to MTO or TBO. 3. Permanent open circuit in any of the CAN stubs. 4. Temporary open circuit in any ECU connector.  Permanent failure of ECU’s.  Temporary failure of ECUs ( due to SW locks ). DIAGNOSTIC GATEWAY Instrument Panel Cluster (IPC) is the Diagnostic Gateway. Diagnostic Gateway is used to prevent the Main vehicle CAN bus from external noise and unauthenticated/ mischievous tools from creating nuisance on the Main CAN bus. All IVN DTCs shall be read through the Diagnostic Gateway i.e Diagnostic tester shall be connected to Diagnostic Gateway which shall route the tester request message to the corresponding ECU and then also route the ECU response back to the tester. IVN DTCs IMPLEMENTED 1. Lost Communication: Bus signal/message failure DTC: Logged when the message is not received from the partner ECU. It is mainly due to partner ECU not connected or not powered up properly 2. Vehicle Communication Bus A: Error Passive / Open Circuit DTC: Logged due to open/short circuit failures in CAN bus. This DTC will be seen as history in all ECUs with CAN diagnostic except the diagnostic gateway (IPC) and K line ECUs 3. Vehicle Communication Bus A: Bus Off DTC: Logged due to open/short circuit failures in CAN bus. This DTC will be seen as history in all ECUs with CAN diagnostic except the diagnostic gateway (IPC) and K line ECUs. 4. Invalid Data received: Invalid Data DTC: This DTC is logged when the partner ECU sends implausible/incorrect value for any of its signal 5. Invalid Data received: MRC DTC: This DTC is logged when the partner ECU does not send continuous updated data. This DTC will be seen as historic (most of the times) 6. Invalid Data received: CRC DTC: This DTC is logged when the partner ECU does not send the correct checksum of critical signals.