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TIAGO/TIGOR AMT Gasoline
DTC Troubleshooting Guide
Version: 4.0
Date: 18-04-2017
Author: Sathi/Anupama
Page: 268 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.
84.
P190C-07: Gearbox System –Control Error
Overview:
ISO Code
P190C-07
Customer Symptom
Transmission Fault Lamp ON
No gearshifts,
Vehicle not picking up ,
vehicle stuck in gear while driving
sudden shift to neutral while driving
Fault Effects (On Vehicle)
No gearshifts,
Vehicle not picking up ,
vehicle stuck in gear while driving
sudden shift to neutral while driving
Lamp Status (If Any)
Transmission Fault Lamp ON
Fault Detection Condition
This fault gets detected after Ignition On during a gearshift
when TCU detects that a gear shift command from TCU is
found to be not responding.
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
Check the kit & gearbox assembly for
mechanical damage, stuck gear actuator,
synchro ring damage, fork damage, gear
damage, lubrication etc?
Go to Step 2
Rectify/replace the
gearbox
2
Check gear electrovalves electrical
connections by following same procedure
as for DTC’s – P0750 & P0755, Are
electrical connections OK?
Go to Step 3
Establish continuity by
rectifying harness
connections as per the
circuit schematic
3
Using TCU diagnostic tool, initiate a grid
learning procedure
Are gears engaging and disengaging freely
and grid learning is successfully executed?
Recheck the above steps
Replace parts in following
order and re-verify:
1>Valve body (MGA)
2>Gearbox
3>Entire Transmission
DTC’s confirmation:-
After rectification, clear all DTC’s and ensure the following points by referring TCU parameters using TML diagnostic tool
before handing over to customer.
Drive the vehicle through all gears in both Automatic and Manual modes