Modern Automotive Technology v
DIAGNOSTIC CASE
STUDY
Concern: Ms. Richmond brings in her
2010 Hyundai. She complains that the
engine oil pressure light comes on at idle
and then goes out when the engine speed is increased.
Cause: Duff checks the oil level on the dipstick. The oil
level is fi ne. The oil is a little dirty but not badly broken
down or burned. Duff then starts the engine and notes
that the oil light fl ickers on and off at idle. He shuts off
the engine and checks the wiring to the oil pressure
sending unit. The wiring tests good, suggesting to Duff
that the oil pressure is low at idle or the sending unit
itself is bad.
Duff passes this information along to the shop’s
engine repair technician and asks him to make any fur-
ther tests needed to pinpoint the cause of the problem.
The technician removes the oil-pressure sending unit
from the engine. He installs an oil-pressure gauge in
the sender socket and starts the engine. The oil pres-
sure gauge reads normal pressure. Because the oil
pressure light illuminates even though oil pressure is
normal, the technician suspects the sending unit.
Correction: The technician installs a new oil-pressure
sending unit, following the service manual instructions.
After the new sending unit is installed, the technician
starts the engine and allows it to idle. Noting that the oil
light no longer fl ickers at idle, the technician releases
the vehicle to the customer.
Safety First, Customer Relations, In the
Rearview Mirror, Industry Trend, Workplace
Skills, Green Tech, and Hybrid Tip Features
Modern Automotive Technology contains a vari-
ety of features designed to generate interest in the
fi eld of automotive technology and cultivate the
skills needed to succeed as an automotive techni-
cian. These features include:
Industry Trend
Industry Trend features highlight new and emerg-
ing technologies in the automotive industry.
Workplace Skills
Workplace Skills features help cultivate the skills
needed to become a successful automotive technician.
Customer Relations
Customer Relations features help develop skills
required to effectively interact with customers.
In the Rearview Mirror
In the Rearview Mirror features chronicle important
milestones in the automobile industry.
Safety First
Safety First features emphasize the importance of
working safely.
Green Tech
Green Tech features detail environmentally friendly
work practices.
Hybrid Tip
Hybrid Tip features highlight the technologies used
in hybrid gas-electric vehicles.
Enhancing the Text
To aid in the learning process, a comprehensive
workbook and a shop manual have been created.
These items are designed to be used with this text.
The workbook contains a variety of questions
that correlate with the textbook, as well as a number
of hands-on activities that help prepare students
to properly complete basic service and repair
procedures.
The shop manual complements the material
presented in the textbook and workbook. It contains
step-by-step jobs covering all the tasks listed in the
NATEF Task List. Both the workbook and shop
manual can be purchased directly from Goodheart-
Willcox Company, Inc.
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