412 / 561
TIAGO/TIGOR AMT Gasoline
DTC Troubleshooting Guide
Version: 4.0
Date: 18-04-2017
Author: Sathi/Anupama
Page: 278 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.
87.
P0942- 07: Hydraulic Circuit – Pump Overheating
Overview:
ISO Code
P0942-07
Customer Symptom
Malfunction in manual upshift/downshift,
earlier/late upshifts/downshifts,
jerky/sluggish gear shifting,
sudden shift to neutral while driving,
No gearshifts
Fault Effects (On Vehicle)
Malfunction in manual upshift/downshift,
earlier/late upshifts/downshifts,
jerky/sluggish gear shifting.
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 if estimated Pump temperature by
TCU exceeds a Threshold.
Normal Operating Condition
Estimated pump temperature by TCU is within normal operating limits.
Probable Trouble Area
Wiring Harness Connections / TCU / Kit
Healing Condition
2000 milliseconds after valid detection of healed condition
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
1
Is the DTC occurring in combination with
any of the DTC’s- P185C, P0942-01,
P0932 or P2712?
Rectify the
other
DTC’s first
Go to Step 2
2
At first occurrence of the problem, clear the
DTC and drive the vehicle in all gears for
about 10 km simulating /in real dense
traffic condition, does the DTC recur?
Go to
Step3
Release vehicle to the customer after final
drive test
3.
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
5
Establish continuity by rectifying harness
connections as per the circuit schematic
4
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
If No pump turn ON:
Go to Step 5
If Pump turns ON but no pressure build up:
Go to Step 6