TIGOR AMT

TIAGO/TIGOR AMT Gasoline

DTC Troubleshooting Guide

Version: 4.0

Date: 18-04-2017

Author: Sathi/Anupama

Page: 274 of 427

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.

86.

P0942- 01: Hydraulic Circuit – Pressure Low

Overview:

ISO Code

P0942-01

Customer Symptom

No gearshifts

Fault Effects (On Vehicle)

No gearshifts

Lamp Status (If Any)

Transmission Fault Lamp ON

Fault Detection Condition

This fault gets detected after Ignition On during pump

commanded ON if hydraulic pressure read by sensor is found

to be below a threshold.

Normal Operating Condition

Hydraulic pressure during normal hydraulic system operation

is between 38-51 bar

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) If this DTC occurs together with P0932 & P185C, it must be rectified last.

2) Loose/ Damaged Connections of Electric Motor and TCU

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

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

5) Check Battery voltage and state of charge.

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

tank/accumulator, Connecting pipes mechanical fitments

7) 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

procedure as for DTC’s – 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 2,

If problem persists Go to

step 4

Rectify/Replace the motor

Replace parts in following order and re-

verify:

If the pump failed to turn ON:

1> Replace the Pump relay

2> Replace the TCU

3> Replace the Kit

Recheck the above steps