DIAGNOSTIC MANUAL

Diagnostic Manual

VEHICLE DIAGNOSTICS

Prior to the integration of control units in vehicles,

technician often had to perform the random

checks to narrow down the suspected area of

problem based on clues and putting together all

of them to diagnoses and fix the problems. This

process of diagnosis was very time consuming &

inaccurate sometimes.

With the introduction of electronic control units

(ECUs) in automobiles, however, the task of

vehicle diagnostics has become simpler. Through

the use of ECUs, technicians can take advantage

of onboard diagnostics to aid them in identifying

possible causes and resolving malfunctions.

Virtually, today all modern vehicles equipped with

On-board diagnostics (OBD), which work with the

ECU to monitor various sub systems & sensors

throughout the vehicle, and log diagnostic trouble

codes (DTC’s) when problems are encountered.

Let’s move forward & understand what OBD is?

Vehicle diagnosis is the technique possessed by

the technician for identifying and analyzing the

possible causes for resolving the customer

complaints.

Historically, effective vehicle diagnostics relied on

the individual skill & competence of a technician,

being able to use visual or audible clues to

correctly assess a vehiclemalfunction. Symptoms

of a mechanical problem can range from the

obvious, such as oil leaking from a faulty seal, to

the indirect, such as rough engine idling. Techni-

cian’s may use wide range of tools & techniques

in conducting vehicle diagnostics, ranging from

physical checks to diagnostics tool based

analysis. Sometimes we may come across

mysterious or intermittent nature of mechanical

problems, in such cases, effective diagnostic is

critical to successful repairs and the smooth

running of any vehicle.