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: 785 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. P0646-11: A/C Clutch Relay Control Circuit Low – Circuit Short to Ground Overview: ISO Code P0646-11 Customer Symptom 1. A/C Clutch may get ON always. 2. May damage the A/C Clutch. Fault Effects (On Vehicle) 1. AC fan /AC compressor will not work. 2.AC load more /less than expected Lamp Status (If Any) CE lamp ON after 1 drive cycle Fault Detection Condition This fault gets logged if the AC Clutch relay control pin of EMS ECU is Short circuited to GND Normal Operating Condition Healthy wiring harness connections between AC Clutch Relay and EMS ECU Probable Trouble Area AC Wiring harness Connections Healing Condition Ignition On and after 1 drive cycle of fault rectification Fault Permanent Deletion 1. Clear DTC Command form Scan tool 2. Stack Over Flow. 3. 40 warm up cycles. 4. ECU Flashing. 5. ECU Power-Fail Component Details: AC Compressor has a magnetic Clutch; Coil of the magnetic clutch is energized by EMS ECU. After getting Energized, Clutch engages the compressor to the EMS ECU. Preliminary Checks: 1) Loose/ Damaged Connections between AC Compressor Relay and EMS ECU. 2) Loose/ Damaged Connections between AC Compressor Relay and Battery supply or Ground. 3) Check for back out of pins at ECU connector. 4) Check for damage of pins at ECU connector. 5) Check the continuity from Relay to the ECU pin and from battery/Ground to Relay.