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TIAGO/TIGOR AMT Gasoline
DTC Troubleshooting Guide
Version: 4.0
Date: 18-04-2017
Author: Sathi/Anupama
Page: 218 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.
69.
P081A-02: Cranking Enable –Short to supply
Overview:
ISO Code
P081A-02
Customer Symptom
Transmission Fault Lamp ON,
Transmission shifting to neutral when engine is OFF
Fault Effects (On Vehicle)
Transmission shifting to neutral when engine is OFF
Lamp Status (If Any)
Transmission Fault Lamp ON
Fault Detection Condition
This fault gets detected after Ignition On when cranking
enable output is commanded OFF and a short circuit to
ground or open circuit is detected.
Normal Operating Condition
TCU does not detect short to ground or open circuit
Probable Trouble Area
Wiring Harness Connections / Electric motor / TCU
Healing Condition
50 milliseconds after valid detection of healed condition
Component Details:
Cranking enable output is a digital output from TCU to EMS which is driven low to allow EMS to crank the Engine safely.
Preliminary Checks:
1) Check for damage/loose fit or back out of pins at TCU 28 pin vehicle connector, & EMS connector.
2) Check for visible damage to TCU or EMS pins.
3) 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 TCU 28 pin vehicle connector,
& EMS connector Terminals?
Clean the Rust or repair or
replace
Go to Step 2
2.
Is there wiring harness electrical continuity
between TCU pin 16 to EMS pin 107? Also
check for any short to battery or ground on
pin 16.
Go to Step 3
Establish continuity by
rectifying harness
connections as per the
circuit schematic
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. Replace the TCU, problem persists?
Replace the EMS
recheck the above steps
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.
Check for proper cranking behavior of the vehicle. i.e. cranking only in neutral gear with brake pressed.
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: