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Automotive Diagnostics : An Introduction

Need of Automotive Diagnostics


Diagnostics is not a inevitable part of the vehicle. A vehicle can run and work even if Diagnostic is not present in any of the ECUs. What makes Diagnostics important is it is quite helpful for the modern process of building, configuring, updating vehicles and making them fail safe in case of failures. We are making vehicle to express and talk about them to external world. 
 Diagnostics is giving easy, secured and universally standardized  access to complex electronic and mechanical system for various purposes.  Below are the different functions which are executed smoothly with the help of Automotive Diagnostics implementation in an ECU. 

Programming, Calibrations :
o   Vehicle has too many Software driven Electronic and mechanical Components nowadays.
o   Some components are configured and  calibrated thorough software after a vehicle is built. Hence an external interface is required to program any Programmable ECU inside already integrated vehicle.
o    ECUs are needed to be Programmable to adapt the SW changes over the time even after vehicle is sold out.

·        Diagnostics :

o   A  Vehicle is being a more Complex  Electro-mechanical system. It has in Vehicle network of physical media connecting ECUs, Sensors , Actuator, HW and Mechanical components. 
o    It can happen when vehicle is moving or stationary. It may or may not be diagnosed and rectified mechanically.
o   Failure of any of components could be fatal.
o   Hence there are ways to  diagnose these fatalities by Self Diagnostics, Off Board Diagnostics, OBD.
o   It may or may not be visual or noticeable to User.
o   To know if system has any failures , every instance shall be kept under check for failures and should be acted upon by electronic systems.
o   A moment of failure shall be meaningfully captured by system.  It shall be capable of capturing Vehicle conditions, In vehicle Network conditions, Electronic and mechanical component information, Occurrences of faults and timestamps at the time of failure.
o   This data can be analyzed by experts for fault rectification. This is part of Off Board Diagnostics.   
   
o   In case of failures Vehicle electronics should be capable of avoiding fatalities by taking fail safe actions.
o   Vehicle shall be made safe by fail safe actions by ECUs if the failures are worth to live with. 
o   User should be made aware if anything fails and system shall not to proceed in case failure at fatal.

·        Off Board Diagnostics :
o   Some failures are hidden and cannot be re-covered or identified by system itself.
o   Hence there is a need to interact with them to gather relevant data for problem analysis and rectification of failures.
o   There is a need to control components externally rather than the from vehicle SW and HW for failure  analysis.
o   Need an interface to electronic components inside a vehicle when in case of failure of HW or SW components.


·        On board Diagnostics :
o   Vehicle Power train systems need to follow Government regulations.
o   Continuous monitoring of the power train related systems is mandate by these regulations.
o   Some parameters shall be able to retrieve from vehicle for OBD
o   This is the basic system available in all the vehicles from Model year onward.
o   This can be said a mother of Diagnostic.


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