TIAGO

TIAGO AMT Gasoline

DTC Troubleshooting Guide

Version: 2.0

Date: 06-06-2016

Author: Sathi/Anupama

Page: 353 of 424

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.

121.

P1844 -07: Grid Self tuning Procedure Error

Overview:

ISO Code

P1844-07

Customer Symptom

Transmission Fault Lamp ON,

No gearshifts ,

Vehicle not picking up

Fault Effects (On Vehicle)

No gearshifts ,

Vehicle not picking up

Lamp Status (If Any)

Transmission Fault Lamp ON

Fault Detection Condition

This fault gets detected after Ignition On if TCU detects that

the Grid self tuning service procedure has not been done or

not successfully completed

Normal Operating Condition

Grid self tuning Procedure is successfully completed at End of

line or after service part replacements (refers service manual)

that require such procedure.

Probable Trouble Area

Wrong execution conditions/Wiring Harness Connections /

TCU

Healing Condition

Immediately after detection of valid Self tuning procedure

completion.

Component Details:

Grid Self tuning procedure is Run through a diagnostic or End of line tool, it is required by the TCU to learn the position of

each gear in the gearbox in terms of its gear and shift position sensor inputs. During this procedure, the TCU also learns the

clutch closed position and clutch stroke.

Preliminary Checks:

1) Before proceeding with rectification, ensure no other DTC in TCU except from a set of P1844,P080A, and P185B. If

s they must be rectified first.

2) Before re-initiating the procedure check the following conditions:

a> Ignition key is ON

b> Transmission in neutral

c> Healthy battery

d> Engine speed is 0

e> Vehicle speed is 0

f> Check correct hydraulic pressure with diagnostic tool (38-51 bar)

g> Brake is not pressed

3) Check for damage or back out of pins at TCU connector.

4) Visibly check for any damage to electro valves/oil leakage/other kit components.

5) Check for loose fitting TCU/EMS and clutch position sensor connectors

6) Check correct fitment of ground cable connections on vehicle chassis.

Trouble Shooting:-

Step Checks

IF YES

IF NO

Rectify the other

clearing

the procedure

again.

Recheck from step

Go to Step 2

Initiate the Grid selftuning procedure with the diagnostic tool, wait

for ~ 2 minutes and ask for routine result.

Check for the below responses and steps to follow: