TIGOR AMT

TIAGO/TIGOR AMT Gasoline DTC Troubleshooting Guide Version: 4.0 Date: 18-04-2017 Author: Sathi/Anupama Page: 62 of 427 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. 19. P1852-01: Clutch Position/Hyd Press Sensor – Wrong supply voltage Gnd Error Overview: ISO Code P1852-01 Customer Symptom Transmission Fault Lamp ON, Loss of power while driving. Engine not cranking Engine stalling at low vehicle speeds No gearshift Fault Effects (On Vehicle) Transmission going automatically to neutral while driving. Engine not cranking Engine stalling at low vehicle speeds No gearshift No EOL self-tuning. Lamp Status (If Any) Transmission Fault Lamp ON Fault Detection Condition This fault gets detected after Ignition On when the Engine is not cranking and battery Supply voltage is in proper range and the clutch position/Hydraulic Pressure sensor supply voltage is found to be lower than acceptable threshold. Normal Operating Condition Clutch position/Hydraulic Pressure sensor supply voltage is regulated at 5 V by TCU Probable Trouble Area Harness or connector damage/short, Sensor loose/damage/short, TCU internal damage Healing Condition 50 milliseconds after valid sensor signal Component Details: Clutch position/Hydraulic Pressure sensor supply voltage is regulated at 5 V by TCU. The clutch position sensor is supplied through pin 12 (12 pin system connector) and hydraulic pressure sensor through internal TCU connection. Preliminary Checks: 1) Loose/ Damaged TCU system connector (12 pin). 2) Check for any visible damage to TCU pins, clutch sensor/hydraulic pressure sensor and its pins. 3) Check correct fitment of ground cable connections on vehicle chassis. Trouble Shooting:- On first occurrence, clear the DTC and drive the vehicle for 2-3 kms, read the DTC again. On fault confirmed again, follow below steps. Step Checks IF YES IF NO 1. Is there any rust/oxidation/pin back out observed on 12 pin system connector pins 1, 8 &12. Clean the Rust or repair or replace Go to Step 2 2. Is there wiring harness electrical continuity between 12 pin system connector pins 1,8 &12.to Sensor connector pins 2,1 &3? Go to Step 3 Establish continuity by rectifying harness connections as per the circuit schematic 3. Are there any pins damaged at Clutch Sensor Connector? Replace the system wiring harness. Go to step 4 4 Is Clutch Sensor Supply Pin (pin 12 of 12 pin system connector) Short circuited to GND/Battery? Repair the harness as per the schematic Go to Step 5 5 Unmount and remove the TCU from the valve body. Inspect the condition of the Hydraulic pressure sensor contacts (refer fig below). Are the sensor contacts visibly undamaged? Go to Step 6 Replace the Hydraulic Pressure sensor/TCU.