TIAGO

TIAGO AMT Gasoline

DTC Troubleshooting Guide

Version: 2.0

Date: 06-06-2016

Author: Sathi/Anupama

Page: 282 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.

88.

P2712- 07: Hydraulic Circuit Leakage too high

Overview:

ISO Code

P2712-07

Customer Symptom

Malfunction in manual upshift/downshift,

earlier/late upshifts/downshifts,

jerky/sluggish gearshifting,

sudden shift to neutral while driving,

No gearshifts

Fault Effects (On Vehicle)

Malfunction in manual upshift/downshift,

earlier/late upshifts/downshifts,

jerky/sluggish gearshifting.

sudden shift to neutral while driving,

No gearshifts

Lamp Status (If Any)

Transmission Fault Lamp ON if level 2 or 3 error(higher in

severity)

Fault Detection Condition

This fault gets detected after Ignition On when gear shifts are

not in progress but TCU detects a leakage of hydraulic oil

greater than a threshold

Normal Operating Condition

Hydraulic oil leakage with electro valves commanded OFF is

within acceptable limits

Probable Trouble Area

Wiring Harness Connections / TCU / Kit

Healing Condition

Fault is cleared on next ignition Power ON

Component Details:

In an AMT system, the hydraulic pump is driven by the TCU whenever the hydraulic pressure read by sensor drops below a

threshold.

Preliminary Checks:

1) Loose/ Damaged Connections of Electric Motor and TCU

2) Check for damage or back out of pins at TCU connector, electric motor connector.

3) Check visibly for kit Oil leakage and oil level.

4) Check Battery voltage and state of charge.

5) Check for mechanical damage to the gearbox loose or damaged valve body/TCU mountings, Hydraulic

tank/accumulator, Connecting pipes mechanical fitments

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

Trouble Shooting:-

Step Checks

IF YES

IF NO

Check Hydraulic pressure sensor and relay

electrical connections by following same

P0932 & P185C

respectively, Are electrical connections

OK?

Go to Step 2

Establish continuity by rectifying

harness connections as per the circuit

schematic

Using TCU diagnostic tool, initiate a

hydraulic pump activation routine and

monitor the hydraulic pressure, does the

pump turn ON audibly and hydraulic

pressure is 38-51 bar?

Clear the DTC and

drive the vehicle

through all gears

for 5 kms

,Recheck the

above steps if fault

recurring

If No pump turn ON:

Go to Step 3

If Pump turns ON but no pressure

build up:

Go to Step 4

Check the Electric motor (refer DTC

P185C), are the connections and

grounding proper?

Replace the motor

and recheck step

If problem persists

Goto step 4

Rectify/Replace the motor