TIGOR AMT

TIAGO/TIGOR AMT Gasoline DTC Troubleshooting Guide Version: 4.0 Date: 18-04-2017 Author: Sathi/Anupama Page: 257 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. 81. P2905-03: Gearbox System –unintended disengage Overview: ISO Code P2905-03 Customer Symptom No gearshifts, Vehicle not picking up , shift to neutral while driving in reverse gear skipping of gears Fault Effects (On Vehicle) No gearshifts, Vehicle not picking up , shift to neutral while driving in reverse gear skipping of gears Lamp Status (If Any) Transmission Fault Lamp OFF Fault Detection Condition This fault gets detected after Ignition On during a gearshift when TCU detects that a gear is unintentionally disengaged without a command. Normal Operating Condition TCU monitors that the time for disengagement/engagement of a gear is within an allowable time Probable Trouble Area Gear Electro valve / TCU / Gearbox Healing Condition Fault is cleared on next ignition Power ON Component Details: In an AMT system, the gear shifting is actuated through 3 electrovalves viz. 2 gear electrovalves for shifting between odd and even gears and 1 shift electrovalves for shifting between ranks. Preliminary Checks: 1) Loose/ Damaged Valve body and TCU mountings. 2) Check for damage or back out of pins at TCU connector. 3) Check visibly for kit Oil leakage and ensure with diagnostic tool that kit oil pressure is in range 38 - 51 bar 4) Check for mechanical damage to the Valve body (MGA), kit and gearbox mechanical fitments 5) Check correct fitment of ground cable connections on vehicle chassis. Trouble Shooting:- At first occurrence of this DTC, clear the DTC and drive the vehicle through all gears for ~5 kms, on repeat occurrence of this DTC check the following. Step Checks IF YES IF NO 1. Through the TML diagnostic tool, Read the Parameters 1)“Sure Engage Threshold EV ON/OFF” 2)”Shift position Threshold” Compare the values to the nominal values and tolerances below: 1 st :xx mm 2 nd :yy mm . . . Are the read values correct within tolerance limits? Go to Step 2 Perform a Grid learning procedure through the TML diagnostic tool, Rerun the vehicle through the drive test. 2. Check the kit & gearbox assembly for mechanical damage, stuck gear actuator, synchro ring damage, fork damage, gear damage, lubrication etc? Go to Step 3 Rectify/replace the gearbox 3. Check gear electrovalves electrical connections by following same procedure Go to Step 4 Establish continuity by rectifying harness