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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: 863 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.
P0490-12: Exhaust Gas Re-circulation Control Circuit High – EGR high pressure valve control out 1 (circuit short
to battery)
Overview:
DTC Description (User Friendly)
EGR high pressure valve control out 1 (circuit short to battery)
ECU Pin Number
A067, A088, A040, A079, A078
Customer Symptom
MIL ON, CEL OFF. No significant symptom, slight rough idle will
be observed
Fault Effects (On Vehicle)
Slight Rough Idle
Lamp Status (If Any)
MIL ON, CEL OFF
Fault Detection Condition (Root cause)
EMS pin A067 Shorted to Supply voltage
Normal Operating Condition
No fault
Probable Trouble Area
Wiring Harness connections between EGR valve and EMS ECU
EGR Valve
Engine Management System
Healing Condition
Rectify the error
Clear through diagnostic tool
Ignition OFF & ON
Component Details:
An incomplete burnt gas in exhaust is return to the cylinder. EGR works by recalculating a portion of an engine's
exhaust gas back to the engine cylinder. Intermixing the incoming air with recalculated exhaust gas dilutes the mix with
inert gas and in turn reduce the combustion temperatures for reducing NOx emissions.
Preliminary Checks:
1. Check whether the customer voice / view about the issue is matching with the fault effects mentioned in above
Table. If yes, go ahead with next steps. If not, check for other DTC’s presence.
2. Check whether other customers report similar complaints earlier. If yes, perform the preliminary checks with
respect to earlier issue closure.\
3. Check for any leakages in EGR flow path.
4. Check whether the EGR valve is physically damaged
5. Check whether the EGR valve is fouling with any other component.
6. Check for damage of pins at ECU connector.
7. Check the wiring harness connections between the EGR valve and EMS ECU.
Trouble Shooting:
Step Checks
IF YES
IF NO
1
Run the EGR High Pressure DC Motor Test Routine. Is the
Routine Result – OK?
Go to Next Step
Rectify the wiring
Harness
connections
between EGR
Valve and EMS
ECU. Repeat the