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TIAGO/TIGOR AMT Gasoline
DTC Troubleshooting Guide
Version: 4.0
Date: 18-04-2017
Author: Sathi/Anupama
Page: 285 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.
89.
P2901- 01: Hydraulic Circuit – Accumulator discharged
Overview:
ISO Code
P2901-01
Customer Symptom
Vehicle cranking after some attempts
Fault Effects (On Vehicle)
Vehicle cranking after some attempts
Lamp Status (If Any)
Transmission Fault Lamp OFF
Fault Detection Condition
This fault gets detected after Ignition On when gear shifts are
not in progress but TCU detects that the charging rate of the
hydraulic accumulator is greater than a threshold.
Normal Operating Condition
Charging rate of the accumulator is below a threshold if it is
not fully discharged.
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. The pump charges an accumulator which stores pressurized hydraulic fluid to be used by shift, engage and clutch
actuators.
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
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
requiring frequent gearshifts , does the DTC
recur?
Go to Step3
Release vehicle to the customer
after final drive test
3
Check the kit assembly for mechanical
damage, sealing, lubrication etc?Is it OK?
Go to Step 4
Rectify/replace the kit
4
Check Hydraulic pressure sensor electrical
connections by following same procedure as
for DTC – P0932, Are electrical connections
OK?
Replace the kit
Establish continuity by rectifying
harness connections as per the
circuit schematic & Release vehicle
to the customer after final drive test
DTC’s confirmation:-
After rectification, clear all DTC’s and ensure the following points by referring TCU parameters using TML diagnostic tool
before handing over to customer.
Read Engineering parameter “High Leakage Error counter” through the diagnostic tool and keep as record
Drive the vehicle through all gears in both Automatic and Manual modes
Ensure no DTC is active and Transmission Fault Lamp is OFF.