TIAGO/TIGOR AMT Gasoline DTC Troubleshooting Guide Version: 4.0 Date: 18-04-2017 Author: Sathi/Anupama Page: 353 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. 121. P1844 -07: Grid Self tuning Procedure – Error Overview: ISO Code P1844-07 Customer Symptom Transmission Fault Lamp ON, No gearshifts , Vehicle not picking up Fault Effects (On Vehicle) No gearshifts , Vehicle not picking up Lamp Status (If Any) Transmission Fault Lamp ON Fault Detection Condition This fault gets detected after Ignition On if TCU detects that the Grid self tuning service procedure has not been done or not successfully completed Normal Operating Condition Grid self tuning Procedure is successfully completed at End of line or after service part replacements (refers service manual) that require such procedure. Probable Trouble Area Wrong execution conditions/Wiring Harness Connections / TCU Healing Condition Immediately after detection of valid Self tuning procedure completion. Component Details: Grid Self tuning procedure is Run through a diagnostic or End of line tool, it is required by the TCU to learn the position of each gear in the gearbox in terms of its gear and shift position sensor inputs. During this procedure, the TCU also learns the clutch closed position and clutch stroke. Preliminary Checks: 1) Before proceeding with rectification, ensure no other DTC in TCU except from a set of – P1844,P080A, and P185B. If there are any other DTC’s they must be rectified first. 2) Before re-initiating the procedure check the following conditions: a> Ignition key is ON b> Transmission in neutral c> Healthy battery d> Engine speed is 0 e> Vehicle speed is 0 f> Check correct hydraulic pressure with diagnostic tool (38-51 bar) g> Brake is not pressed 3) Check for damage or back out of pins at TCU connector. 4) Visibly check for any damage to electro valves/oil leakage/other kit components. 5) Check for loose fitting TCU/EMS and clutch position sensor connectors 6) Check correct fitment of ground cable connections on vehicle chassis. Trouble Shooting:- Step Checks IF YES IF NO 1. Connect the TCU diagnostic tool and check for active DTC’s, are there any active DTC’s other than the current one? Rectify the other DTC’s first. After clearing DTC’s, run the procedure again. Recheck from step 1 Go to Step 2 2 Initiate the Grid selftuning procedure with the diagnostic tool, wait for ~ 2 minutes and ask for routine result. Check for the below responses and steps to follow: - -
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