Advance System 2 Midterm Review Questions

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)

Typical TP sensor voltage at idle is about ___.

0.5 volt or 10% of WOT TP sensor voltage

With the TP sensor in the position shown, what voltage would be expected at the signal wire (C)

0.5 volts

When the concentration of oxygen on the exhaust side of the thimble is low (rich exhaust), a voltage of _______ is generated between the electrodes

0.60-1.0

An oxygen sensor is being tested using a digital storage oscilloscope (DSO). A good oxygen sensor should display how many switches per second

1-5

A wide band oxygen sensor is capable of detecting the air-fuel mixture in the exhaust from _____ (rich) to_____ (lean)

10:1 to 23:1

To determine the air-fuel mixture ratio if Lamdba is given, multiple Lambda times_____.

14.7

The primary purpose of the fuel trim is to keep the air-fuel mixture as close to _________ as possible

14.7:1

The air at high altitude has

21% oxygen

A Lambda of 0.97 means that the engine is operating _________ rich and has an air-fuel mixture of _________.

3%,14.3:1

An IAT is being tested. After the vehicle has been allowed to cool for several hours, a scan tool is used to observe the IAT sensor reading. When compared to the engine coolant temperature (ECT), the two temperature should be within how many degrees F of each other

5

With the vehicle in closed loop, the following post converter HO2S scope pattern activity is seen. What dose this indicate

A bad converter

With the vehicle in closed loop, the following post converter HO2S scope pattern activity is seen. What dose this indicate

A good converter

A typical MAP sensor compares the vacuum in the intake manifold to ___.

A perfect vacuum

Fuel valves can be read using

A scan tool

Which statement is false?

Absolute pressure is equal to barometric pressure plus intake manifold vacuum

What is NOT true about short-term fuel trim?

Can add or subtract a large amount of fuel

When testing an ECT sensor on a vehicle, a digital multimeter can be used and the signal wire back probed. Which setting should the tech use to test the sensor

DC volts

Which of these can be used to measure the frequency (Hz) output of the sensor and compare the reading with specifications

DMM (Digital multimeter)

Which is NOT a function of a TP sensor

Determining rich and lean air-fuel mixtures

The sensor that most determine fuel delivery when a fuel injected engine is first started is the ________.

ECT sensor

Air that enters the engine without passing through the airflow sensor is called

False air

Where is sensor 1, bank 1 located on a V-type engine

In the exhaust manifold and on the same bank where number 1 cylinder is located

A large amount of oxygen in the exhaust system causes the oxygen to produce which of these

Low voltage

Which of the following components measures the volume and density of the incoming air

Mass Airflow Sensor

In the below illustration what type of circuit is depicted

Negative temperature coefficient (NTC) thermistor

The sensor that must be warmed and functioning before the engine management computer will go to closed loop is the _____

O2S

Fuel trim provides a method that is capable of changing the amount of fuel delivered to the engine based on feedback from which of these input sensors?

Oxygen sensor

The wiring to the IAT sensor has high resistance (cut wire). What could this cause

Poor fuel economy and Black exhaust smoke

The component shown (shaded) has crack or split in it. What would this cause?

Poor running in a forward gear but OK in reverse and allows false air into the engine

Oxygen sensor cross counts can only be determined using a

Scan tool

Which of these components lets the PCM know how fast you want to accelerate

TP sensor

A P0132 DTC is being discussed. Tech A says that a defective HO2S could be the cause. Tech B says that an HO2S signal wire shorted-to-ground could be the cause. Which tech is correct

Tech A

Tech A says that a MAF sensor is a high-authority sensor and is responsible for determining the fuel needs of the engine based on the measured amount of air entering the engine. Tech B says that a cold wire MAF sensor uses the electronics in the sensor itself to heat a wire 20°F below the temperature of the air entering the engine. Which tech is correct

Tech A

Tech A says that an oxygen sensor produces a voltage output signal based on the oxygen content of the exhaust stream. Tech B says that of the exhaust has little oxygen the voltage of the oxygen sensor will be close to 0 volts. Which tech is correct

Tech A

Tech A says that the primary purpose of fuel trim is to keep the air-fuel ratio is as close to 14.7:1 as possible. Tech B says that when the air-fuel ratio is at 14.7:1, the efficiency of the catalytic converter is the lowest. When tech is correct?

Tech A

Tech A says that the TP sensor signal voltage should be about 0.5 volt at idle and increase to about 2.5 volts at wide-open throttle (WOT). Tech B says that a TP sensor can be tested using a DMM (digital multimeter), DSO (digital storage oscilloscope), or scan tool. Which tech is correct

Tech B

A MAP sensor is being tested. Tech A says that many MAP sensors also acts as a barometric pressure sensor when the ignition switch is first turned on. Tech B says many MAP sensors the signal voltage should increase when the vacuum at the sensor deceases. Which tech is correct

Tech C

Tech A says that MAP sensors uses a 5-volt reference voltage from the PCM. Tech B says that the MAP sensor voltage will be higher at idle at high altitudes compared to when the engine is operating at near sea level. When tech is correct

Tech C

Tech A says that the ECT and IAT sensor can be tested visually, as well as by using a digital multimeter or a scan tool. Tech B says that the ECT sensor is a high-authority sensor at engine startup and is used for open-loop control, as well as idle speed. Which tech is correct

Tech C

Tech A says that the purpose of the intake air temperature (IAT) sensor is provide the engine computer (PCM) with the temperature of the air entering the engine. Tech B says the the IAT sensor information is used for fuel control (adding or subtracting fuel) and sparking timing, depending on the temperature of incoming air. Which tech is correct

Tech C

The MAP and BARO sensor may be the same sensor

True

Injector pulse width is measured in

millisecond