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:
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