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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: 825 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.
P0402-22: EGR “A” Flow Excessive Detected – The maximum control deviation exceeds the upper limit
Overview:
DTC Description (User Friendly)
The maximum control deviation exceeds the upper limit
ECU Pin Number
A067, A088, A040, A079, A078
Customer Symptom
MIL ON, CEL OFF, Cruise Control will not work, Torque Limited,
Black Smoke may come.
Fault Effects (On Vehicle)
Cruise control off, Torque limited, Rail Pressure Regulator Off
Lamp Status (If Any)
MIL ON, CEL OFF
Fault Detection Condition (Root cause)
The limit for the maximum permissible positive control deviation of
the exhaust−gas recirculation control has been exceeded.
Normal Operating Condition
The limit for the maximum permissible positive control deviation of
the exhaust-gas recirculation control not been reached (healing
next driving cycle)
Probable Trouble Area
Intake or Exhaust system Problem
EGR air flow control valve binding
EGR System leak
EGR Valve
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 clogging in Inlet Air Circuit.
4. Check for any leakages in EGR flow path.
5. Check whether the EGR valve is physically damaged
6. Check for any Air Mass Flow Sensor / Exhaust related faults presence. If so, rectify them.
7. Check for any faults related to atmospheric sensor. If so, rectify them by following their rectification procedure.
8. Check for damage of pins at ECU connector.
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
Routine Test again.