Page 339 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

LESSON 104 - 107 : Details of trouble codes functions

of sensors and actuators-details of
scan tool-precautions while working

with sensors and actuators

Objectives

At the end of this lesson you shall be able to
• read trouble codes of sensors and actuators.
• demonstrate use of scan tool.

Sensors: Sensors are the components of the system that provide the inputs that enable the computer (ECM) to
carry out the operations that make the system function correctly.
In the case of vehicle sensors, it is usually a voltage that is represented by a code at the computer’s processor. If
this voltage is incorrect the processor will probably take it as an invalid input and record a fault.

Engine development has become a challenge mainly because the user expects improved performance levels with
reduced fuel consumption. Further, environmental considerations necessitate adopting the use of methods which
lower emissions. Achieving the twin goal of low emissions with good performance and drivability is a difficult task.
It is in this context that electronic engine management has gained importance. The principal aims of an engine
developer is to achieve:
i High reliability and durability with lowest possible initial cost
ii High power output and torque
iii Low levels of gaseous and particulate emissions

iv Low fuel consumption
v Low noise levels and vibrations

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