, Question 1
A Toyota vehicle with a 2GR-FE engine exhibits a P0301 DTC. Live data
shows fuel trims at +18% on bank 1, and a cylinder leak-down test indicates
15% leakage with air escaping from the oil filler cap. Which of the following is
the MOST likely cause?
A. Faulty ignition coil on cylinder 1
B. Worn piston rings or cylinder wall
C. Leaking intake manifold gasket
D. Clogged fuel injector on cylinder 1
Correct Answer: B - Worn piston rings or cylinder wall
RATIONALE
Air escaping from the oil filler cap during a leak-down test indicates
leakage past the piston rings or cylinder walls. Positive fuel trims
suggest a lean condition, but the mechanical leak is the primary cause
of the misfire. Ignition or fuel issues would not cause air to escape
into the crankcase.
Question 2
During a road test of a Toyota hybrid vehicle, the technician notices that the
engine starts and stops frequently at low speeds, and the battery state of charge
fluctuates rapidly. Which component is MOST likely responsible for this
behavior?
A. Faulty hybrid battery pack
B. Malfunctioning inverter with converter
C. Worn brake actuator
D. Defective engine coolant temperature sensor
Correct Answer: B - Malfunctioning inverter with converter
Page 2
, RATIONALE
The inverter with converter manages power flow between the hybrid
battery and electric motors, and also controls engine start/stop. A
malfunction can cause erratic engine cycling and rapid SOC changes.
A faulty battery would show different symptoms, and brake or coolant
sensors would not directly cause this.
Question 3
A Toyota vehicle with a smart key system fails to start when the brake pedal is
pressed, but the engine cranks. The smart key indicator blinks, and a DTC
B2799 is stored. Which of the following is the MOST appropriate next step?
A. Replace the smart key battery
B. Check the brake pedal position switch circuit
C. Perform a certification ECU (smart key ECU) reset
D. Inspect the engine control module (ECM) power supply
Correct Answer: C - Perform a certification ECU (smart key
ECU) reset
RATIONALE
DTC B2799 indicates a communication error between the certification
ECU and ECM, often requiring a reset or re-registration. While brake
switch issues can prevent starting, the presence of B2799 points to a
smart key system communication fault. Replacing the key battery or
checking brake switch would not address the DTC.
Question 4
A Toyota Tundra with a 5.7L V8 exhibits a P0171 and P0174 (lean banks 1 and
2). Fuel pressure is within specification, and there are no vacuum leaks. Live
data shows the mass air flow (MAF) sensor reading is lower than expected.
Which of the following is the MOST likely cause?
A. Contaminated MAF sensor
B. Faulty fuel pump
Page 3
, C. Leaking intake manifold gasket
D. Clogged fuel filter
Correct Answer: A - Contaminated MAF sensor
RATIONALE
A contaminated MAF sensor can underreport airflow, causing the
ECM to reduce fuel delivery and set lean codes on both banks. Fuel
pressure and vacuum leaks are ruled out. A faulty fuel pump or
clogged filter would typically affect both banks but would also show
low fuel pressure.
Question 5
When diagnosing a Toyota vehicle with a parasitic draw, the technician
measures a 50 mA draw after all modules have gone to sleep. Which of the
following is the MOST likely cause?
A. A faulty alternator diode
B. A stuck relay in the integration relay
C. A defective body control module (BCM)
D. A shorted door lock actuator
Correct Answer: B - A stuck relay in the integration relay
RATIONALE
A stuck relay can continue to power a circuit after the vehicle is off,
causing a parasitic draw. 50 mA is higher than the typical 20-30 mA
specification. Alternator diodes usually cause a draw only when the
engine is off, but a stuck relay is a common cause. BCM or actuator
issues would typically show different symptoms or higher draws.
Page 4
A Toyota vehicle with a 2GR-FE engine exhibits a P0301 DTC. Live data
shows fuel trims at +18% on bank 1, and a cylinder leak-down test indicates
15% leakage with air escaping from the oil filler cap. Which of the following is
the MOST likely cause?
A. Faulty ignition coil on cylinder 1
B. Worn piston rings or cylinder wall
C. Leaking intake manifold gasket
D. Clogged fuel injector on cylinder 1
Correct Answer: B - Worn piston rings or cylinder wall
RATIONALE
Air escaping from the oil filler cap during a leak-down test indicates
leakage past the piston rings or cylinder walls. Positive fuel trims
suggest a lean condition, but the mechanical leak is the primary cause
of the misfire. Ignition or fuel issues would not cause air to escape
into the crankcase.
Question 2
During a road test of a Toyota hybrid vehicle, the technician notices that the
engine starts and stops frequently at low speeds, and the battery state of charge
fluctuates rapidly. Which component is MOST likely responsible for this
behavior?
A. Faulty hybrid battery pack
B. Malfunctioning inverter with converter
C. Worn brake actuator
D. Defective engine coolant temperature sensor
Correct Answer: B - Malfunctioning inverter with converter
Page 2
, RATIONALE
The inverter with converter manages power flow between the hybrid
battery and electric motors, and also controls engine start/stop. A
malfunction can cause erratic engine cycling and rapid SOC changes.
A faulty battery would show different symptoms, and brake or coolant
sensors would not directly cause this.
Question 3
A Toyota vehicle with a smart key system fails to start when the brake pedal is
pressed, but the engine cranks. The smart key indicator blinks, and a DTC
B2799 is stored. Which of the following is the MOST appropriate next step?
A. Replace the smart key battery
B. Check the brake pedal position switch circuit
C. Perform a certification ECU (smart key ECU) reset
D. Inspect the engine control module (ECM) power supply
Correct Answer: C - Perform a certification ECU (smart key
ECU) reset
RATIONALE
DTC B2799 indicates a communication error between the certification
ECU and ECM, often requiring a reset or re-registration. While brake
switch issues can prevent starting, the presence of B2799 points to a
smart key system communication fault. Replacing the key battery or
checking brake switch would not address the DTC.
Question 4
A Toyota Tundra with a 5.7L V8 exhibits a P0171 and P0174 (lean banks 1 and
2). Fuel pressure is within specification, and there are no vacuum leaks. Live
data shows the mass air flow (MAF) sensor reading is lower than expected.
Which of the following is the MOST likely cause?
A. Contaminated MAF sensor
B. Faulty fuel pump
Page 3
, C. Leaking intake manifold gasket
D. Clogged fuel filter
Correct Answer: A - Contaminated MAF sensor
RATIONALE
A contaminated MAF sensor can underreport airflow, causing the
ECM to reduce fuel delivery and set lean codes on both banks. Fuel
pressure and vacuum leaks are ruled out. A faulty fuel pump or
clogged filter would typically affect both banks but would also show
low fuel pressure.
Question 5
When diagnosing a Toyota vehicle with a parasitic draw, the technician
measures a 50 mA draw after all modules have gone to sleep. Which of the
following is the MOST likely cause?
A. A faulty alternator diode
B. A stuck relay in the integration relay
C. A defective body control module (BCM)
D. A shorted door lock actuator
Correct Answer: B - A stuck relay in the integration relay
RATIONALE
A stuck relay can continue to power a circuit after the vehicle is off,
causing a parasitic draw. 50 mA is higher than the typical 20-30 mA
specification. Alternator diodes usually cause a draw only when the
engine is off, but a stuck relay is a common cause. BCM or actuator
issues would typically show different symptoms or higher draws.
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