Week #2 - Chapter 3 Flashcards
As the load on an engine increases, the manifold vacuum decreases and the manifold absolute pressure ________.
Increases
A TP sensor is what type of sensor?
Potentiometer
Typical TP sensor voltage at idle is about ________.
0.5 volt or 10% of WOT TP sensor voltage
When checking the ECT sensor with a scan tool, about what temperature should be displayed if the connector is removed from the sensor with the key on, engine off?
-40°F (-40°C)
Two technicians are discussing a stepped ECT circuit. Technician A says that the sensor used for a stepped circuit is different than one used in a non-stepped circuit. Technician B says that a stepped ECT circuit uses different internal resistance inside the PCM. Which technician is correct?
Both Technicians A and B
A typical NTC sensor decreases in resistance as the temperature ________.
Increases
An oxygen sensor is being tested using a Min-Max on a digital meter set to read the average. A good oxygen sensor should display what reading?
450 mv
A high O2S voltage could be due to ________.
A rich exhaust
The voltage output of a zirconia oxygen sensor, when the exhaust stream is lean (excess oxygen), is ________.
Relatively low (close to 0 volts)
The typical MAF reading on a scan tool with the engine at idle speed and normal operating temperature is ________.
3 to 7 grams per second
A fuel‑injection system that does not use a sensor to measure the amount (or mass) of air entering the engine is usually called a(n) ________ type of system.
Speed density
Silicon-diaphragm strain gauge, capacitor-capsule, and ceramic disc are examples of which sensors?
MAP sensors
The relationship among atmospheric pressure, vacuum, and boost pressure in psi is that atmospheric pressure is measured in inches of Mercury. What is this measurement?
About 29.50 in. Hg
The wires on a typical three wire TP sensor consist of a signal wire from the TP sensor to the PCM, ground, and ________ reference.
5 Volt
Visual inspection, resistance, and using a scan tool to monitor the operation (reading) of the sensor as the engine operates are the three ways to test which sensors?
Temperature sensors
Zirconia, titanium and wide-band are the three basic designs of which sensors?
Oxygen (O2) sensors
An oxygen sensor detects oxygen levels in the exhaust by comparing the oxygen levels between the ________ and the ________.
Exhaust, Outside air
Hot film, hot wire and Karman Vortex are the types of which sensors?
Airflow sensors
How is a MAF sensor tested?
By visual inspection, output voltage/frequency and a scan tool
A hot film MAF sensor uses a circuit that monitors the amount of current needed to keep the hot film ________ above the temperature of the incoming air .
70 C
The three uses of a ________ by the PCM are to determine the load on the engine, to determine altitude for fuel and spark control, and to monitor and test for proper EGR operation.
MAP sensor
Most computer-equipped engines use a ________ to signal the position of the throttle to the computer.
Throttle position sensor
Coolant sensors have a very high resistance when the coolant is cold and a low resistance when the coolant is hot. This is referred to as ________.
Negative temperature coefficient (NTC)
Idle air control, oxygen sensor closed loop, and idle speed are additional inputs from which sensor?
The ECT sensor
What are three ways oxygen sensors can be tested?
By using a digital voltmeter (using min/max), a scan tool, or a scope
