442 / 4910
Q501 4 Cylinder MT Application
DTC Troubleshooting Data
Version: 0.1
Date: 21-Sep-2018
Prepared By: Mithi Prasad, Sarang Kulkarni, Manish Gupta
Checked By: Yogesh Jadhav
Approved By: Satish Kumar P
Page: 410 of 1052
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.
P1277-14: Plausibility check Vsensing short to gound or open circuit during crank
Overview:
DTC Description as per ISO standard
Plausibility check Vsensing short to gound or open circuit
during crank – short to ground or open circuit
ECU Pin Number
K85
Customer Symptom
CEL ON
Fault Effects (On Vehicle)
Starter relay will engage
Lamp Status (If Any)
CEL ON
Fault Detection Condition (Root cause)
This fault gets logged under the following conditions:
Ignition ON and Starter Relay control pin of EMS ECU is short
circuited to Battery.
Normal Operating Condition
Diagnostic tool display the battery voltage, crank input &
engine RPM status during cranking
Probable Trouble Area
Starter Relay, ECU Main relay, ECU, Wiring harness
Healing Condition
Clear the errors, Ignition OFF to ON, engine idle & fly-up
condition
Component Details:
Starter Relay activates the Starter solenoid for vehicle starting. EMS energizes the starter relay if all the pre-conditions
Required for starter motor engagement are fulfilled.
Preliminary Checks:
1. Check whether the customer voice / view about the issue is matching with the fault effects mentioned above. If
yes, go ahead with next steps. If not, check for other DTC’s presence.
2. Check whether similar complaints are earlier reported. If yes, perform the preliminary checks with respect to
earlier issue closure. Check for pin back out at EMS ecu connector or EGR valve connector.
3. Check whether relay contacts weld / Stuck open or not. If found open, then rectify/replace it
4. Check whether there are any pins damaged at EMS ECU Connector. If found faulty then replace the connector or
wiring harness
5. Check whether there are any pins backed out from the EMS ECU Connector. If found faulty then replace the
Connector or wiring harness.
6. Check whether the starter relay is connected in vehicle.