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Nexon Gasoline – EMS ECU Bosch
DTC Troubleshooting Manual
Version: 0.1
Date: 26-08-2017
Prepared By: Sunu S Babu/Yogesh Jadhav
Checked By: Yeshwant Jadhav
Approved By: Satish Kumar
Document Part No: 2921 02 224 A1736
Page: 38 of 1203
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.
Preliminary Checks:
1) Loose/ Damaged Connections between Actuator and EMS ECU.
2) Check for back out of pins at both Actuator connector and ECU connector.
3) Check for damage of pins at both Actuator connector and ECU connector.
4) Check the continuity from Actuator connector pins to the ECU pins.
Trouble Shooting:
Step Checks
IF YES
IF NO
1.
Is there any rust/oxidization observed on VVT
actuator Terminals
Clean the Rust or repair
or replace
Go to Step 2
2. Is there wiring harness electrical continuity
between ECU pin 249 & VVT EX actuator pin 1
Go to Step 3
Establish continuity by
rectifying harness
connections as per the
Circuit schematic
3. Are there any pins damaged at VVT actuator /EMS
ecu Connector
Replace the connector
or wiring harness
Go to step 4
4
Are there any pins backed out from the VVT
Actuator/EMS ecu Connector
Rectify/Replace
Connectors
Go to Step 5
5
Is VVT Actuator pin 249 Open Circuited
Go to Step 6
Repair the harness as
per the schematic
6
Is VVT Actuator physically Damaged
Replace VVT
Go to Step 7
7.
Are there any metallic particles/Burr in VVT
actuators Tip?
Clean those burr/metallic
particles
Go to step 8
8
Are there any faults related to VVT Actuators
power supply voltages
Replace these faults by
following their
rectification procedure
Go to step 9
9
Fault Still Persists?
Replace VVT Actuator
and then Fault still
persists then Replace
EMS ecu
Follow the steps again
for reconfirmation
DTC’s confirmation:-
After rectification, ensure the following points by referring engine parameters using TML diagnostic tool before
handing over to customer.
1. Fuel system status
2. Engine load
3. Engine coolant temperature.
4. Long term fuel trim.
5. MAP Sensor.
6. Engine Speed.
7. Vehicle Speed.
8. Spark timing.
9. Absolute throttle position.
10. Distance Travelled after MIL ON.
11. Distance travelled since fault memory last cleared.
12. Battery voltage.
Recheck the fault, fault shall not reappear.