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TIAGO AMT Gasoline
DTC Troubleshooting Guide
Version: 2.0
Date: 06-06-2016
Author: Sathi/Anupama
Page: 23 of 424
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.
6.
P1853-02: Gear/shift Position Sensor Wrong supply voltage Vbatt Error
Overview:
ISO Code
P1853-02
Customer Symptom
Transmission Fault Lamp ON,
Transmission going automatically to neutral while driving.
No gearshifts.
Engine not cranking
Creeping inactive
Fault Effects (On Vehicle)
Transmission going automatically to neutral while driving.
No gearshifts
Engine not cranking
Creeping inactive
No EOL self-tuning.
Lamp Status (If Any)
Transmission Fault Lamp ON
Fault Detection Condition
This fault gets detected after Ignition On when the Engine is not cranking and
battery Supply voltage is in proper range and the gear/shift position sensor
supply voltage is found to be higher than acceptable threshold.
Normal Operating
Condition
gear/shift position sensor supply voltage is regulated at 5 V by TCU
Probable Trouble Area
Sensor supply short (internal)/ TCU internal damage
Healing Condition
50 milliseconds after valid sensor signal
Component Details:
Gear/shift position sensor supply voltage is regulated at 5 V by TCU. Connections are internal to TCU.
Preliminary Checks:
1) Check for any visible damage to TCU.
2) Check correct fitment of ground cable connections on vehicle chassis.
Trouble Shooting:-
On first occurrence, clear the DTC and drive the vehicle for 2-3 kms, read the DTC again. On fault confirmed again, follow
below steps.
Step Checks
IF YES
IF NO
1.
Unmount and remove the TCU from the valve
body. Inspect the condition of the gear/shift
position sensor connections (refer fig below).
Check for any short/damaged sensor wires. Are
sensor connections visibly undamaged?
Go to Step 2
Replace the sensor/TCU.
2. Replace the TCU
-
the following points by referring TCU parameters using TML diagnostic tool
before handing over to customer.
Drive the vehicle through all gears in both Automatic and Manual modes.
Ensure no DTC is active and Transmission Fault Lamp is OFF.
Circuit Schematic Diagram: