Page 336 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Precautions to be observed while working with engine

emission control systems details of OBD-description of
data link connect or study about schematic and routing

diagram of emission control system flow diagram of control

systems-terminal arrangement of ECM

Objectives: At the end of this lesson you shall be able to
• demonstrate precautions to be observed while working with engine emission control systems
• study about schematic and routing diagram of emission control system.

Precautions to be observed while working with engine emission control systems
The exhaust gas of diesel engine vehicles contains high amount of nitrogen oxide (NOx), sulfur dioxide and
particulate matter. For pollution control of vehicles with diesel engines, attention should be paid to the following
aspects.
1 Engine oil should be changed after regular intervals. Use the correct grade of oil as per the vehicle manufacturer’s
instructions.
2 Change the oil filter, fuel filter and air filter after certain period and use good quality and good company.

3 Proper grade of fuel should be used. Fuel pump and fuel injector should be serviced after a certain period of
time. Also other works related to engine servicing (eg tappet setting etc.) should be done.
4 Maintain the entire vehicle as per service manual.

5 Avoid driving with over load and over speed.
6 Emission level should be checked regularly.
The Government of India has decided the Emission Norms (GLKM) from 1st April 2000 and they are (EIRO - I, II,
III, IV) as Bharat Stage 1, Bharat Stage II, Bharat Stage III, Called Bharat Stage IV. While issuing PUC (Pollution
Under Control) certificate, the amount of harmful element in the exhaust gas is checked with the help of exhaust
gas analyzer. According to the revised rules, the transport department allows the vehicle to be driven on the road
only if it is in the right amount.
Details of OBD-description of data link connect or study about schematic and routing diagram of emission
control system
The On-Board Diagnostics (OBD) system is an internal part of vehicles as it is monitors the engine, transmission,
and other emissions-related systems. This system utilizes a standardized digital communications port known as
the data link connector (DLC), to provide real-time data and diagnostic information.
The DLC serves as the physical connector or port where an OBD scanner or diagnostic tool is connected to
access the vehicle’s data. Typically located beneath the dashboard, near the driver’s seat, the DLC follows a
standardized format across vehicles and is commonly a 16-pin connector. However, older vehicles may feature a
12-pin connector instead.
Each pin within the DLC has a specific purpose:
- Pin 4 and Pin 5: Ground
- Pin 16: Battery voltage
- Pin 7: K-Line (ISO 9141-2 and ISO 14230-4)

- Pin 2: Bus+ (SAE J1850 PWM and VPW)
- Pin 10: Bus- (SAE J1850 PWM only)
- Pins 6, 14, and 15: CAN High, CAN Low, and CAN Ground (ISO 15765-4)
- Pins 1, 3, 8, 9, 11, 12, 13: Manufacturer discretion for additional functions

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CITS : Automotive - Mechanic Diesel - Lesson 98 - 103 CITS : Automotive - Mechanic Diesel - Lesson 98 - 103