Question 1

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

Accepted Answer

The O2S (oxygen sensor) is the sensor that must be warmed and functioning before the engine management computer will go to closed loop. It measures the oxygen content in the exhaust gases and provides feedback to the engine management computer, which adjusts the air-fuel ratio to maintain optimal combustion efficiency. The other sensors listed (ECT sensor, BARO sensor, and MAP sensor) do not have a direct effect on the closed loop operation.

Question 2

Where is sensor 1, bank 1 located?

Accepted Answer

Sensor 1, bank 1 is located on the same bank where number 1 cylinder is located and in the exhaust manifold. Therefore, the correct answer is D, both A and B.

Question 3

A heated Zirconia oxygen sensor will have how many wires?

Accepted Answer

Heated zirconia oxygen sensors can have either 3 or 4 wires. The additional wires are used for the heater element, which helps the sensor reach its operating temperature more quickly.

Question 4

When testing an oxygen sensor using a DSO (digital storage oscilloscope), how quickly should the voltage change when either propane is added to the intake stream or when a vacuum leak is created?

Accepted Answer

The voltage should change quickly, within less than 100ms, indicating a rapid response from the oxygen sensor. This quick response time ensures accurate and timely adjustments to the air/fuel ratio.

Question 5

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

Accepted Answer

Technician A is correct because an oxygen sensor does indeed produce a voltage output signal that varies with the oxygen content in the exhaust stream. Technician B is incorrect because when the exhaust has little oxygen (indicating a rich mixture), the voltage of the oxygen sensor will be higher, not close to 0 volts.

Question 6

Technician A says that oxygen sensors can have one, two, three, four, or more wires, depending on the style and design. Technician B says that if the exhaust has little oxygen, the voltage of the oxygen sensor will be close to 1 volt (1000 mV) and close to zero if there is high oxygen content in the exhaust. Which technician is correct?

Accepted Answer

Technician A is correct in stating that oxygen sensors can have different numbers of wires depending on the style and design. Some may have one wire while others can have up to four or more.
Technician B is correct in stating that the voltage of the oxygen sensor will be close to 1 volt when the exhaust has little oxygen, and close to zero when there is high oxygen content in the exhaust. This is because the oxygen sensor's primary function is to measure the amount of oxygen in the exhaust and adjust the air/fuel ratio accordingly. As the oxygen content changes, so does the voltage produced by the sensor.

Question 7

Technician A says that oxygen sensors can be tested using a test light or dwell meter, or a scan tool. Technician B says that conditions can occur that cause the oxygen sensor to be fooled and give a false lean or false rich signal to the PCM. Which technician is correct?

Accepted Answer

The answer of Technician A says that oxygen sensors can...

Question 8

A P0131 DTC is being discussed. Technician A says that an exhaust leak upstream of HO2S (bank 1) oxygen sensor could be the cause. Technician B says that an extremely rich air-fuel mixture could be the cause. Which technician is correct?

Accepted Answer

Technician A is correct because an exhaust leak upstream of HO2S (bank 1) oxygen sensor can allow excess oxygen that will not be accounted for by the oxygen sensor and can result in a false lean reading. Technician B is incorrect because an extremely rich air-fuel mixture could cause a P0172 DTC (system too rich), not P0131. P0131 is a low voltage reading from HO2S (bank 1) oxygen sensor, indicating a lean condition.

Question 9

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

Accepted Answer

The answer of A P0132 DTC is being discussed. Technician...

Question 10

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

Accepted Answer

When the concentration of oxygen on the exhaust side of the thimble is low, indicating a rich exhaust condition, a voltage of 0.60-1.0 volts is typically generated between the electrodes of an oxygen sensor. This voltage signal is used by the vehicle's engine control unit to adjust the fuel mixture.

Question 11

A large amount of oxygen in the exhaust system causes the O2S (Oxygen sensor) to produce which of these?

Accepted Answer

A large amount of oxygen in the exhaust system decreases the voltage output of the oxygen sensor, causing it to produce low voltage readings.

Question 12

What does the post, or downstream, oxygen sensor (HO2S) measure?

Accepted Answer

The post or downstream oxygen sensor (HO2S) measures the amount of oxygen behind the catalytic converter. This helps to determine if the catalytic converter is functioning properly to reduce harmful emissions.

Question 13

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

Accepted Answer

The answer of With the vehicle in closed loop, the...

Question 14

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

Accepted Answer

The pattern indicates a bad converter.

Question 15

The two internal chambers of a dual cell wide band oxygen sensor include ________ and ________.

Accepted Answer

The two internal chambers of a dual cell wide band oxygen sensor include an air reference chamber and a diffusion chamber. These two chambers work together to accurately measure the amount of oxygen in the exhaust gases. The air reference chamber contains a reference gas that is exposed to the outside air, while the diffusion chamber is exposed to the exhaust gases. The difference in the oxygen concentration between these two chambers allows the sensor to generate an accurate signal that can be used by the engine control module to adjust fuel delivery and ensure optimal engine performance. The Nernst and Pump are components within the sensor, but not the two internal chambers.

Question 16

When the air/fuel ratio is expressed as lambda, a lambda number of less than 1 indicates a(n) ________ exhaust.

Accepted Answer

When the lambda number is less than 1, it means there is less oxygen (O2) in the exhaust than the ideal air/fuel ratio of 14.7:1. This indicates that there is an excess of unburned fuel, which characterizes a rich exhaust.

Question 17

Technician A says that a wide-band oxygen sensor, also called a lean air-fuel (LAF) sensor, can detect air-fuel ratios from as rich as 10:1 to as lean as 23:1. Technician B says that the oxygen sensor signal determines fuel trim which is used to tailor the air-fuel mixture for the catalytic converter. Which technician is correct?

Accepted Answer

Technician A is correct about the detection range of a wide-band oxygen sensor. Technician B is also correct in stating that the oxygen sensor signal is used to determine fuel trim, which is then used to adjust the air-fuel ratio for the catalytic converter. Therefore, both technicians A and B are correct.

Question 18

In some hybrid electric vehicles, the wide band oxygen sensor can cause the PCM to enter closed loop ________.

Accepted Answer

In some hybrid electric vehicles, the wide band oxygen sensor can cause the PCM to enter closed loop as soon as the engine (ICE) starts.

Question 19

Most service information specifies that a(n) ________ be used when testing a wide band oxygen sensor.

Accepted Answer

Most service information specifies that a factory scan tool should be used when testing a wide band oxygen sensor, as it provides more accurate and detailed readings than a generic scan tool.

Question 20

On a poorly running engine, the wide band oxygen sensor can be quickly checked by ________.

Accepted Answer

Disconnecting the sensor connector is the best choice to quickly check the wide band oxygen sensor on a poorly running engine. This will allow the technician to visually inspect the sensor and its wiring for any obvious issues or damage. Disconnecting the battery or jumping the connector with a wire or flashlight battery can potentially damage the vehicle's electronics or the sensor itself.

Quiz 19: Oxygen Sensors

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

Where is sensor 1, bank 1 located?

A heated Zirconia oxygen sensor will have how many wires?

When testing an oxygen sensor using a DSO (digital storage oscilloscope) , how quickly should the voltage change when either propane is added to the intake stream or when a vacuum leak is created?

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

Technician A says that oxygen sensors can be tested using a test light or dwell meter, or a scan tool. Technician B says that conditions can occur that cause the oxygen sensor to be fooled and give a false lean or false rich signal to the PCM. Which technician is correct?

A P0131 DTC is being discussed. Technician A says that an exhaust leak upstream of HO2S (bank 1) oxygen sensor could be the cause. Technician B says that an extremely rich air-fuel mixture could be the cause. Which technician is correct?

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

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

A large amount of oxygen in the exhaust system causes the O2S (Oxygen sensor) to produce which of these?

What does the post, or downstream, oxygen sensor (HO2S) measure?

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

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

The two internal chambers of a dual cell wide band oxygen sensor include and .

When the air/fuel ratio is expressed as lambda, a lambda number of less than 1 indicates a(n) ________ exhaust.

In some hybrid electric vehicles, the wide band oxygen sensor can cause the PCM to enter closed loop ________.

Most service information specifies that a(n) ________ be used when testing a wide band oxygen sensor.

On a poorly running engine, the wide band oxygen sensor can be quickly checked by ________.

Quiz 19: Oxygen Sensors

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

Where is sensor 1, bank 1 located?

A heated Zirconia oxygen sensor will have how many wires?

When testing an oxygen sensor using a DSO (digital storage oscilloscope) , how quickly should the voltage change when either propane is added to the intake stream or when a vacuum leak is created?

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

Technician A says that oxygen sensors can be tested using a test light or dwell meter, or a scan tool. Technician B says that conditions can occur that cause the oxygen sensor to be fooled and give a false lean or false rich signal to the PCM. Which technician is correct?

A P0131 DTC is being discussed. Technician A says that an exhaust leak upstream of HO2S (bank 1) oxygen sensor could be the cause. Technician B says that an extremely rich air-fuel mixture could be the cause. Which technician is correct?

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

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

A large amount of oxygen in the exhaust system causes the O2S (Oxygen sensor) to produce which of these?

What does the post, or downstream, oxygen sensor (HO2S) measure?

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

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

The two internal chambers of a dual cell wide band oxygen sensor include ________ and ________.

When the air/fuel ratio is expressed as lambda, a lambda number of less than 1 indicates a(n) ________ exhaust.

In some hybrid electric vehicles, the wide band oxygen sensor can cause the PCM to enter closed loop ________.

Most service information specifies that a(n) ________ be used when testing a wide band oxygen sensor.

On a poorly running engine, the wide band oxygen sensor can be quickly checked by ________.

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

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

The two internal chambers of a dual cell wide band oxygen sensor include and .