TIAGO

TIAGO AMT Gasoline

DTC Troubleshooting Guide

Version: 2.0

Date: 06-06-2016

Author: Sathi/Anupama

Page: 230 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.

73.

P2904-01: Clutch System Not opening before shift

Overview:

ISO Code

P2904-01

Customer Symptom

No gearshifts,

Automatic gear shift mode disabled (manual mode always)

Fault Effects (On Vehicle)

No gearshifts,

Automatic gear shift mode disabled

Lamp Status (If Any)

Transmission Fault Lamp OFF

Fault Detection Condition

This fault gets detected after Ignition On before a gearshift

when clutch is commanded open but found to be not

responding.

Normal Operating Condition

TCU detects correct clutch response during clutch opening for

gearshift

Probable Trouble Area

Clutch Electro valve / TCU / Clutch

Healing Condition

Fault is cleared on next successful gear shift

Component Details:

In an AMT system, the clutch is electro-hydraulically controlled by the TCU.

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 clutch housing, clutch actuator mechanical fitments

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

Trouble Shooting:-

Step Checks

IF YES

IF NO

Check the clutch assembly and AMT clutch

lever interface for mechanical damage,

stuck particle, lubrication loss etc?

Go to Step 2

Rectify/replace the

component

Check clutch electrovalve electrical

connections by following same procedure

as for DTC P0900. Are electrical

connections OK?

Go to Step 3

Establish continuity by

rectifying harness

connections as per the

circuit schematic

Using TCU diagnostic tool, initiate clutch

actuation routine.

changes from engaged (~xxx mm) to

disengaged (yyy mm) position.

(Alternately visibly check the clutch lever

movement with actuation command.)

Is the clutch engaging and disengaging

freely?

Recheck the above steps

Replace the valve body

(Mechatronic gear

Actuator),

if fault persists then

Replace Kit

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

Ensure no DTC is active and Transmission Fault Lamp is OFF.

Circuit Schematic Diagram: