Deck 15: European Bosch Computerized Engine Controls

Question 1

Early Motronic idle speed controls are being discussed. Technician A says an idle air bypass device is used to increase idle speed when the engine is cold. Technician B says the rotary idle control valve is used to control idle speed at any engine temperature. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Answer 1

C

Question 2

Which statement regarding air-fuel ratio is correct?

A)The ideal air-fuel ratio is known as stoichiometric
B)The ideal air-fuel ratio is known as lambda
C)Both statements are correct.
D)Neither statement is correct.

Answer 2

C

Question 3

Which of the following sensors is commonly used on a Bosch Motronic system to allow the PCM to distinguish between engine misfire and an erratic crankshaft signal caused by rough road surfaces?

A)Chassis accelerometer
B)MEMS gyrometer
C)Yaw sensor
D)VSS

Answer 3

A

Question 4

A Motronic system controls all of the following EXCEPT for the:

A)fuel injectors
B)fuel pump relay
C)ignition timing
D)cold-start injector

Question 5

What is the primary advantage of using a cold start fuel injector?

A)It allows for a richer air/fuel ratio when starting a cold engine.
B)It allows more time for the fuel to vaporize when starting a cold engine.
C)It allows for the use of a lower octane fuel when starting a cold engine.
D)It allows the PCM to shut down the primary fuel injectors when starting a cold engine.

Question 6

What is the principal input used by an L-Jetronic system to determine how much fuel to inject?

A)Fuel pressure
B)Manifold pressure
C)Air flow
D)Intake temperature

Question 7

Which statement about a turbocharged engine Motronic system is correct?

A)The system uses boost pressure reduction to control spark knock.
B)The system uses spark retard to control spark knock
C)Both statements are correct.
D)Neither statement is correct.

Question 8

Which of these inputs is NOT used by the PCM to modify the read-only map for ignition timing?

A)Intake air temperature
B)Engine coolant temperature
C)Air flow
D)Altitude

Question 9

The Motronic system is able to perform "plausibility" test on the MAF sensor. What does this mean?

A)It compares the MAF sensor value to a predetermined value stored in the ROM memory
B)It compares the MAF sensor value to a calculated value based on Air temperature and engine speed
C)It compares the MAF sensor value to a calculated value based on throttle position and engine speed
D)It compares the MAF sensor value to a calculated value based on throttle position and engine coolant temperature

Question 10

The Motronic electronic transmission control is being discussed. Technician A says it momentarily retards ignition timing during transmission shifting. Technician B says the PCM controls the automatic transmission's shift points using spool-type shift valves. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 11

Why does the main power relay on a Bosch Motronic fuel injection system contain a diode?

A)To protect the PCM against voltage surges
B)To protect the PCM against accidental polarity reversals
C)To keep the relay energized in case of relay circuit driver failure within the PCM
D)Both A and B are correct

Question 12

The pulse-width control map is being discussed. Technician A says it functions as the look-up table the PCM uses to determine injector pulse width. Technician B says the map values are stored in the PCM's read-only memory and cannot be modified. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 13

Cranking mode is being discussed. Technician A says extra injector pulses may be used to richen the mixture. Technician B says an extra injector may be used to richen the mixture. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 14

Which of these statements about knock sensors is correct?

A)The sensor generates a voltage signal
B)The sensor generates a frequency signal
C)The sensor is located in the cylinder head
D)On V-type engines, one sensor is used

Question 15

Bosch pulsed multipoint injection systems are being discussed. Technician A says the injectors may be operated sequentially. Technician B says the injectors may be operated in clustered groups. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 16

Technician A says that European vehicles may have two data link connectors - an OBD II standardized DLC under the instrument panel and a manufacturer proprietary DLC designed for dealership scan tools. Technician B says that modern European vehicles will have a CAN data bus that will connect with the OBD II DLC. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 17

Which feature is unique to the Bosch K-Jetronic injection system?

A)The injectors are electronically controlled
B)The opening of the air valve controls a fuel metering valve.
C)The system uses sensors to regulate fuel control
D)The system uses manifold pressure to determine engine load

Question 18

Motronic fuel systems are being discussed. Technician A says the fuel pump is directly controlled by the PCM. Technician B says some systems use a pulse damper to regulate fuel pressure. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 19

What is the principal difference between the L-Jetronic and LH-Jetronic systems?

A)The method used to determine fuel delivery
B)The type of air flow sensor used
C)The type of injectors used
D)The type of management system used

Question 20

The injectors are being serviced on a Bosch fuel injection system. Technician A says the seals often leak and should be inspected carefully any time the injectors are removed. Technician B says petroleum jelly is generally regarded as the best O-ring installation lubricant. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B