Question 1

Two technicians are discussing the purpose of OBD-II compliant systems for automotive diesel engines. Technician A says that an OBD-II compliant system is designed to identify or self-diagnose emission-related faults and report fault codes. Technician B says the OBD-II rules are set up to enable drivers to have emissions problems repaired quickly and easily. Who is correct?
A)Technician A"
B)Technician B"
C)Both A and B
D)Neither A nor B"

Accepted Answer

OBD-II systems are indeed designed to identify emission-related faults and report fault codes (Technician A), and the rules are intended to facilitate quick and easy repairs of emissions problems (Technician B).

Question 2

A diagnostic approach using OBD (on-board diagnostic) data is unlike a symptom-based diagnostic strategy-a problem is identified based on a:
A)cause"
B)complaint"
C)condition
D)problem"

Accepted Answer

The answer of A diagnostic approach using OBD (on-board diagnostic)...

Question 3

Which of these OBD (on-board diagnostic) codes are also vital for technicians to validate before returning a vehicle to the customer?
A)System readiness codes"
B)System fault codes"
C)Diagnostic trouble codes
D)Fault readiness codes"

Accepted Answer

System readiness codes are vital for technicians to validate before returning a vehicle to the customer because they indicate whether the vehicle's emission control systems are functioning properly and have been tested.

Question 4

Technician A says that in North America, only the EPA (Environmental Protection Agency) outlines standards for OBD (on-board diagnostic) system operation for vehicles operated over the road. Technician B says that the European On-Board Diagnostics (EOBD) and OBD legislation and regulations should not be confused with enhanced OBD codes, which refer to manufacturer-specific or proprietary diagnostic codes. Who is right?
A)A only"
B)B only"
C)Both A and B
D)Neither A nor B"

Accepted Answer

The EPA is not the only body that outlines standards for OBD systems in North America; CARB (California Air Resources Board) also plays a significant role. Technician B is correct in stating that EOBD and OBD legislation should not be confused with enhanced OBD codes, which are manufacturer-specific.

Question 5

What attached to the body near the engine compartment designates vehicles that comply with either federal EPA (Environmental Protection Agency) or California Air Resource Board (CARB) emission standards?
A)EPA/CARB label"
B)Emission decal label"
C)Monroney label
D)Emission systems Label"

Accepted Answer

The answer of What attached to the body near the...

Question 6

Technical standards for OBD (on-board diagnostic) are developed by the
A)EPA (Environmental Protection Agency)"
B)CARB (California Air Resource Board)"
C)OEM (original equipment manufacturer)
D)SAE (Society of Automotive Engineers)"

Accepted Answer

The Society of Automotive Engineers (SAE) is responsible for developing technical standards for on-board diagnostics (OBD) systems.

Question 7

From its inception, an essential function of the OBD (on-board diagnostic) system was its use as a tool for emissions inspection and maintenance programs, often called:
A)emission tests"
B)SMOG tests"
C)I/M (inspection maintenance) tests
D)Federal Test Procedures (FTP)"

Accepted Answer

The answer of From its inception, an essential function of...

Question 8

A CARB (California Air Resource Board)-certified Tier 2 bin 5 vehicle has a Federal Test Procedures (FTP) protocol limiting NOx to no more than:
A)0.05 grams/mile"
B)0.07 grams/mile"
C)0.10 grams/mile
D)0.12 grams/mile"

Accepted Answer

A CARB-certified Tier 2 bin 5 vehicle has a FTP protocol limiting NOx to no more than 0.05 grams/mile.

Question 9

An enhanced OBD-II code will be indicated by which position in the SAE code structure?
A)last digit."
B)last two digits."
C)first two digits.
D)second digit."

Accepted Answer

The answer of An enhanced OBD-II code will be indicated...

Question 10

Technician A says that a pending fault will not have a DTC that can be retrieved by a scanner or electronic service tool. Technician B says a pending fault will never have freeze-frame data associated with it. Who is correct?
A)Technician A"
B)Technician B"
C)Both A and B
D)Neither A nor B"

Accepted Answer

Pending faults do have a DTC that can be retrieved by a scanner, and they can have freeze-frame data associated with them.

Question 11

Which of the following is a set of prescribed driving cycles performed on a chassis dynamometer which should not to be confused with emissions limits?
A)FTP (federal test procedures)"
B)MI (malfunction indicators)"
C)DTC (diagnostic trouble codes)
D)Blink codes"

Accepted Answer

FTP (Federal Test Procedures) are standardized driving cycles used to evaluate vehicle emissions and fuel economy on a chassis dynamometer, distinct from emissions limits themselves.

Question 12

Which of the following is NOT included in the OBDII (On Board Diagnostic Generation II) systems for diesel engines?
A)Standardization of a 12-pin diagnostic connector link (DLC) in the driver area"
B)Standardization of SAE generic emission-related fault codes across all manufacturers"
C)Standardized network communication at the DLC
D)Mandatory reporting of standardized emission-related data at the DLC"

Accepted Answer

The OBDII systems use a 16-pin diagnostic connector, not a 12-pin connector.

Question 13

The SAE standard J-1962 specifies that the D-shaped DLC must contain ---___ terminals.
A)6"
B)9"
C)12
D)16"

Accepted Answer

The SAE standard J-1962 specifies that the D-shaped Data Link Connector (DLC) must contain 16 terminals.

Question 14

The CAN module messages are transmitted over a pair of wires called a:
A)wiring bus"
B)bar bus"
C)data bus
D)information bus"

Accepted Answer

The CAN (Controller Area Network) module messages are transmitted over a "data bus," which is a communication system that transfers data between components inside a computer or between computers.

Question 15

Which of the following is the latest network communication protocol, which has an international standard described in ISO 14229-1:
A)SAE J1850 VPW (variable pulse width)"
B)LAN (Local Area Network)"
C)SAE J1850 PWM (pulse-width modulation)
D)UDS (Unified Diagnostic Service)"

Accepted Answer

UDS (Unified Diagnostic Service) is the latest network communication protocol with an international standard described in ISO 14229-1.

Question 16

Which of the following narrow down the location of a fault or abnormal system condition but require further testing to differentiate between several possible root causes and verify the root cause?
A)FTP (federal test procedures)"
B)MI (malfunction indicators)"
C)DTC (diagnostic trouble codes)
D)Blink codes"

Accepted Answer

Diagnostic Trouble Codes (DTC) help identify the area of a fault or abnormal condition in a system but require further testing to pinpoint the exact root cause.

Question 17

If a coolant temperature sensor shorted to ground, which emissions system monitor would first detect the fault?
A)cooling system monitor."
B)rationality monitor."
C)comprehensive component monitor (CCM).
D)network communication monitor."

Accepted Answer

The comprehensive component monitor (CCM) is responsible for detecting faults in various sensors and components, including the coolant temperature sensor.

Question 18

Technician A says that if all the sensors and components of the aftertreatment system are removed, the OBD-II system will not be able to detect faults in the absence of electrical signals. Technician B says that the comprehensive component monitor (CCM) will set emission-related fault codes. Who is correct?
A)Technician A"
B)Technician B"
C)Both A and B
D)Neither A nor B"

Accepted Answer

The CCM is designed to monitor the performance of the aftertreatment system and will set emission-related fault codes if it detects any problems.

Question 19

The ________ data that the ECM (engine control module) stores will provide a snapshot of the engine operating conditions at the moment when the DTC (diagnostic trouble code) was confirmed by the OBD system.
A)freeze-frame"
B)control frame"
C)service information
D)service record"

Accepted Answer

Freeze-frame data captures the engine's operating conditions at the time a diagnostic trouble code is set, providing valuable information for diagnosing issues.

Question 20

Leaving the filler cap off a diesel fuel tank is an indication of:
A)a major emission monitor associated with it"
B)there not being a major emission monitor associated with it"
C)a minor emission monitor associated with it
D)a connection to a major emission monitor"

Accepted Answer

Leaving the filler cap off a diesel fuel tank does not trigger a major emission monitor, as diesel engines do not have the same evaporative emission control systems as gasoline engines.

Quiz 19: On Board Diagnostics

A diagnostic approach using OBD (on-board diagnostic) data is unlike a symptom-based diagnostic strategy-a problem is identified based on a:

Which of these OBD (on-board diagnostic) codes are also vital for technicians to validate before returning a vehicle to the customer?

What attached to the body near the engine compartment designates vehicles that comply with either federal EPA (Environmental Protection Agency) or California Air Resource Board (CARB) emission standards?

Technical standards for OBD (on-board diagnostic) are developed by the

From its inception, an essential function of the OBD (on-board diagnostic) system was its use as a tool for emissions inspection and maintenance programs, often called:

A CARB (California Air Resource Board) -certified Tier 2 bin 5 vehicle has a Federal Test Procedures (FTP) protocol limiting NOx to no more than:

An enhanced OBD-II code will be indicated by which position in the SAE code structure?

Technician A says that a pending fault will not have a DTC that can be retrieved by a scanner or electronic service tool. Technician B says a pending fault will never have freeze-frame data associated with it. Who is correct?

Which of the following is a set of prescribed driving cycles performed on a chassis dynamometer which should not to be confused with emissions limits?

Which of the following is NOT included in the OBDII (On Board Diagnostic Generation II) systems for diesel engines?

The SAE standard J-1962 specifies that the D-shaped DLC must contain ---___ terminals.

The CAN module messages are transmitted over a pair of wires called a:

Which of the following is the latest network communication protocol, which has an international standard described in ISO 14229-1:

Which of the following narrow down the location of a fault or abnormal system condition but require further testing to differentiate between several possible root causes and verify the root cause?

If a coolant temperature sensor shorted to ground, which emissions system monitor would first detect the fault?

The ________ data that the ECM (engine control module) stores will provide a snapshot of the engine operating conditions at the moment when the DTC (diagnostic trouble code) was confirmed by the OBD system.

Leaving the filler cap off a diesel fuel tank is an indication of: