HEXA

ELECTRICAL 156 Diagnostics tool connection problem: A) Steps to be followed to solve diagnostic tool connectivity issue: Do Ignition Off Step 1. Check Diagnostic tool communication 1. if K line based ECUs (FATC, TOC and Airbag ECU only communicating) then check CAN wired for resistance 2. If only CAN based ECUs (xxxxx) are communicating - then check K line wire continuity from OBD II connector pin no 7 (TBC) to IC Pin noxx(TBC) 3. If above is ok, and if all ECUS are not connecting through tool then check Diagnostics Fuse in cabin fuse box (5A), if found faulty. 4. if still not working then, check installation so the SAMTECK drivers and TML diagnostics tool installations in service Laptop / computer. B) If still there is diagnostic tool connectivity issue: 1. Check CAN resistance between - a. Measure resistance of vehicle CAN bus between PIN no 8 (CAN H) and PIN No 9 (CHA L) in OBD connector. If resistance is 60 Ohm (+/- 5Ohm), then bus is OK. b. Measure resistance of diagnostics CAN bus between PIN no 6 (CAN H) and PIN No 14 (CHA L) in OBD connector. If resistance is 120Ohm (+/- 10Ohm), then bus is OK. Measure resistance between CANH and GND, CANL and GND:  If resistance is in ~ K-Ohm, then no short circuit between the wires.  If it is less than 10 Ohm, there is short circuit between the two wires 2. Measure resistance between CANH and Batt, CANL and Batt  If resistance is in ~ K-Ohm, then no short circuit between the wires.  If it is less than 10 Ohm, there is short circuit between the two wires 3. Check continuity between IPC CAN_H (pin no. 6) vehicle side connector to OBD connector CAN_H (pin no. 6) and CAN_L (pin no. 14) vehicle side connector to ODB connector (pin no.14). 4. Fix the failures in harness CAN termination Module introduction The Termination module is required as a separate external module in the CAN network in case internal termination resistor is not present in ECU. The termination module is located in the cabin fuse box. The termination module is present in the following vehicle variants as follows: 1. XE variant – termination module is present in Vehicle CAN 2. XT variant – termination module is present in ESP private CAN CAN termination Module Electrical details The termination module has a resistance value of ~120 Ohms. This can be measured between pin no 3 (CAN H) and pin no 5 (CAN L). Diagnostic Test of Termination module The CAN network can be affected if the termination module is damaged or disconnected from the CAN bus. In case CAN Bus Off or CAN open circuit failure DTC is observed, one probable cause could be that CAN termination module is disconnected/damaged. For this to be verified, check if CAN bus termination resistance is approx. 60 Ohms. If the resistance value is not correct then proceed to verify the termination module resistance. Remove the termination module from the Cabin fuse box and measure the termination resistance. It should be 120 Ohms. Refit the termination module in the cabin fuse box and check if the vehicle CAN termination resistance is showing 60 Ohms. If issue is still present, then proceed to check other areas like CAN lines are short circuited etc