340 / 561
TIAGO/TIGOR AMT Gasoline
DTC Troubleshooting Guide
Version: 4.0
Date: 18-04-2017
Author: Sathi/Anupama
Page: 206 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.
65.
P185C-01: Hydraulic pump Supply –Short to ground
Overview:
ISO Code
P185C-01
Customer Symptom
Transmission Fault Lamp ON,
No gearshifts,
sudden shift to neutral while driving
Engine not cranking
Fault Effects (On Vehicle)
No gearshifts,
sudden shift to neutral while driving
Engine not cranking
Lamp Status (If Any)
Transmission Fault Lamp ON
Fault Detection Condition
This fault gets detected after Ignition On when hydraulic pump
output supply is commanded ON and a short circuit to ground
is detected on the supply.
Normal Operating Condition
TCU does not detect short to ground
Probable Trouble Area
Wiring Harness Connections / Electric motor / TCU
Healing Condition
1000 milliseconds after valid detection of healed condition
Component Details:
Hydraulic pump supply output is used to drive the hydraulic pump which supplies pressurized hydraulic oil for kit actuators.
Preliminary Checks:
1) Loose/ Damaged Connections between hydraulic pump motor and TCU.
2) Check for damage or back out of pins at TCU 12 pin system connector, hydraulic pump motor connector & TCU pins.
3) Check for visible damage to Electric motor.
4) Check correct fitment of ground cable connections on vehicle chassis.
Trouble Shooting:-
Step Checks
IF YES
IF NO
1.
Is there any rust/oxidation/damage
observed on Electric Motor (refer fig below)/
TCU /12 pin system connector Terminals?
Clean the Rust or repair or
replace
Go to Step 2
2.
Is there wiring harness electrical continuity
between TCU pin 7 to electric motor
connector pin? Also check for any short to
battery or ground on pin 7.
Go to Step 3
Establish continuity by
rectifying harness
connections as per the
circuit schematic/replace
the system pigtail harness
if defective.
3
Check the TCU ignition and power
connections on Pins 5, 1 and 3 respectively.
Check for ignition pin toggling to 12 V with
ignition key On-Off. Connections are OK?
Go to Step 4
Establish continuity by
rectifying harness
connections as per the
circuit schematic
4.
With all electrical connections fully
connected and only the motor 1 pin
connector open, monitor the voltage output
at motor 1 pin connector.
With the TML diagnostic tool, Actuate the
hydraulic pump.
Is 12 V observed at the motor connector
after command ON for some time (~10 sec)
and 0 V later?
Go to step 5
Go to step 7
5
Refit the motor connector and With the TML
diagnostic tool, Actuate the hydraulic pump.
Clear the DTC and recheck
the above steps.
Go to step 6