USPS Exams 943, 944, 945 Actual Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf.
1. Exam 943 is used to hire which type of USPS maintenance position?
A. Maintenance Support Clerk
B. Automotive Mechanics responsible for routine maintenance and repair
C. Automotive Technicians responsible for complex repairs
D. Mail Processing Equipment Mechanics
Answer: B. Exam 943 is a technical test used to hire Automotive Mechanics who perform
routine types of maintenance and repair on USPS vehicles. Exam 944 is used for
Automotive Technicians who handle more complex maintenance and repair.
2. What is the primary difference between the responsibilities of Exam 943 and
Exam 944 positions?
A. Exam 943 positions work on mail processing equipment; Exam 944 positions work on
vehicles
B. Exam 943 positions handle routine maintenance; Exam 944 positions handle complex
repairs
C. Exam 943 positions are entry-level; Exam 944 positions are supervisory
D. There is no difference
Answer: B. Exam 943 is for Automotive Mechanics who perform routine types of
maintenance and repair. Exam 944 is for Automotive Technicians who handle more
complex maintenance and repair.
3. A USPS vehicle is brought in with a complaint of excessive vibration at highway
speeds. The technician should FIRST check:
A. Engine oil level
B. Tire balance and wheel alignment
C. Transmission fluid level
D. Brake pad thickness
,Answer: B. Excessive vibration at highway speeds is most commonly caused by
unbalanced tires or misalignment. Tire balance and wheel alignment should be the first
areas inspected.
4. During a preventive maintenance inspection, the technician finds a loose drive
belt. What is the MOST appropriate corrective action?
A. Tighten the belt to the manufacturer's specified tension
B. Replace the belt only if it shows visible wear
C. Apply belt dressing to stop squealing
D. Ignore it until the next service
Answer: A. A loose drive belt should be tightened to the manufacturer's specified tension.
If the belt is worn or damaged, it should be replaced. Belt dressing is a temporary fix and
not a proper repair.
5. A technician is diagnosing a no-start condition on a USPS delivery vehicle. The
battery tests at 12.4 volts, but the engine does not crank when the key is turned.
The MOST likely cause is:
A. Dead battery
B. Faulty starter motor or starter relay
C. Empty fuel tank
D. Clogged air filter
Answer: B. A battery reading 12.4 volts is sufficiently charged. If the engine does not
crank, the issue is likely in the starting circuit—starter motor, starter relay, or ignition
switch.
6. What type of fire extinguisher is rated for use on flammable liquid fires
(gasoline, oil, grease)?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: B. Class B fire extinguishers are designed for flammable liquid fires, including
gasoline, oil, and grease. Class A is for ordinary combustibles, Class C for electrical fires,
and Class D for combustible metals.
7. When working on a vehicle's electrical system, what is the FIRST safety step?
A. Disconnect the negative battery cable
B. Remove the positive battery cable first
,C. Wear rubber gloves only
D. Disconnect the battery while the engine is running
Answer: A. The first and most crucial safety step when working on a vehicle's electrical
system is to disconnect the negative battery cable to prevent electrical shocks and short
circuits.
8. In a gasoline engine, fuel ignition is initiated by a:
A. Spark plug arc
B. Compression heat
C. Glow plug
D. Fuel injector spray
Answer: A. Gasoline engines use spark ignition—an electrical arc from the spark plug
ignites the compressed air-fuel mixture. Compression heat is characteristic of diesel
engines.
9. What is the most common cause for excess tire wear on the edges?
A. Overinflation
B. Underinflation
C. Improper wheel balance
D. Misaligned caster
Answer: B. Underinflation causes the tire's tread edges to wear more rapidly than the
center because the tire flattens and puts more pressure on the shoulders.
10. Not enough positive caster will cause:
A. Hard steering
B. Vehicle wandering and instability
C. Inside tire wear
D. Outside tire wear
Answer: B. Insufficient positive caster causes the vehicle to wander and feel unstable
because the wheels lack self-centering action.
11. What is the correct procedure for checking the engine oil level on a USPS
vehicle?
A. Check when the engine is running
B. Check when the engine is off and on level ground
, C. Check immediately after turning off the engine
D. Check only during oil changes
Answer: B. Engine oil should be checked with the engine off, on level ground, and after
the oil has had time to drain back to the oil pan for an accurate reading.
12. A technician is testing a vehicle's charging system. The battery voltage with
the engine running at 2,000 RPM should be approximately:
A. 12.0 volts
B. 12.6 volts
C. 13.5–14.5 volts
D. 15.5 volts
Answer: C. A properly functioning charging system should produce 13.5–14.5 volts at the
battery with the engine running. 12.6 volts is the static battery voltage with the engine off.
13. Which component converts mechanical energy from the engine into electrical
energy to charge the battery?
A. Battery
B. Starter motor
C. Alternator
D. Distributor
Answer: C. The alternator converts mechanical energy from the engine (via the drive belt)
into electrical energy to charge the battery and power electrical systems.
14. The vibration damper on an engine is also known as a:
A. Harmonic balancer
B. Flywheel
C. Flexplate
D. Pulley
Answer: A. The vibration damper is also called a harmonic balancer. It absorbs torsional
vibrations from the crankshaft to prevent fatigue failure.
15. Hydrocarbons (HC) in exhaust emissions are primarily caused by:
A. High combustion temperature
B. Lean air-fuel mixture
C. Misfire
D. Open EGR valve
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf.
1. Exam 943 is used to hire which type of USPS maintenance position?
A. Maintenance Support Clerk
B. Automotive Mechanics responsible for routine maintenance and repair
C. Automotive Technicians responsible for complex repairs
D. Mail Processing Equipment Mechanics
Answer: B. Exam 943 is a technical test used to hire Automotive Mechanics who perform
routine types of maintenance and repair on USPS vehicles. Exam 944 is used for
Automotive Technicians who handle more complex maintenance and repair.
2. What is the primary difference between the responsibilities of Exam 943 and
Exam 944 positions?
A. Exam 943 positions work on mail processing equipment; Exam 944 positions work on
vehicles
B. Exam 943 positions handle routine maintenance; Exam 944 positions handle complex
repairs
C. Exam 943 positions are entry-level; Exam 944 positions are supervisory
D. There is no difference
Answer: B. Exam 943 is for Automotive Mechanics who perform routine types of
maintenance and repair. Exam 944 is for Automotive Technicians who handle more
complex maintenance and repair.
3. A USPS vehicle is brought in with a complaint of excessive vibration at highway
speeds. The technician should FIRST check:
A. Engine oil level
B. Tire balance and wheel alignment
C. Transmission fluid level
D. Brake pad thickness
,Answer: B. Excessive vibration at highway speeds is most commonly caused by
unbalanced tires or misalignment. Tire balance and wheel alignment should be the first
areas inspected.
4. During a preventive maintenance inspection, the technician finds a loose drive
belt. What is the MOST appropriate corrective action?
A. Tighten the belt to the manufacturer's specified tension
B. Replace the belt only if it shows visible wear
C. Apply belt dressing to stop squealing
D. Ignore it until the next service
Answer: A. A loose drive belt should be tightened to the manufacturer's specified tension.
If the belt is worn or damaged, it should be replaced. Belt dressing is a temporary fix and
not a proper repair.
5. A technician is diagnosing a no-start condition on a USPS delivery vehicle. The
battery tests at 12.4 volts, but the engine does not crank when the key is turned.
The MOST likely cause is:
A. Dead battery
B. Faulty starter motor or starter relay
C. Empty fuel tank
D. Clogged air filter
Answer: B. A battery reading 12.4 volts is sufficiently charged. If the engine does not
crank, the issue is likely in the starting circuit—starter motor, starter relay, or ignition
switch.
6. What type of fire extinguisher is rated for use on flammable liquid fires
(gasoline, oil, grease)?
A. Class A
B. Class B
C. Class C
D. Class D
Answer: B. Class B fire extinguishers are designed for flammable liquid fires, including
gasoline, oil, and grease. Class A is for ordinary combustibles, Class C for electrical fires,
and Class D for combustible metals.
7. When working on a vehicle's electrical system, what is the FIRST safety step?
A. Disconnect the negative battery cable
B. Remove the positive battery cable first
,C. Wear rubber gloves only
D. Disconnect the battery while the engine is running
Answer: A. The first and most crucial safety step when working on a vehicle's electrical
system is to disconnect the negative battery cable to prevent electrical shocks and short
circuits.
8. In a gasoline engine, fuel ignition is initiated by a:
A. Spark plug arc
B. Compression heat
C. Glow plug
D. Fuel injector spray
Answer: A. Gasoline engines use spark ignition—an electrical arc from the spark plug
ignites the compressed air-fuel mixture. Compression heat is characteristic of diesel
engines.
9. What is the most common cause for excess tire wear on the edges?
A. Overinflation
B. Underinflation
C. Improper wheel balance
D. Misaligned caster
Answer: B. Underinflation causes the tire's tread edges to wear more rapidly than the
center because the tire flattens and puts more pressure on the shoulders.
10. Not enough positive caster will cause:
A. Hard steering
B. Vehicle wandering and instability
C. Inside tire wear
D. Outside tire wear
Answer: B. Insufficient positive caster causes the vehicle to wander and feel unstable
because the wheels lack self-centering action.
11. What is the correct procedure for checking the engine oil level on a USPS
vehicle?
A. Check when the engine is running
B. Check when the engine is off and on level ground
, C. Check immediately after turning off the engine
D. Check only during oil changes
Answer: B. Engine oil should be checked with the engine off, on level ground, and after
the oil has had time to drain back to the oil pan for an accurate reading.
12. A technician is testing a vehicle's charging system. The battery voltage with
the engine running at 2,000 RPM should be approximately:
A. 12.0 volts
B. 12.6 volts
C. 13.5–14.5 volts
D. 15.5 volts
Answer: C. A properly functioning charging system should produce 13.5–14.5 volts at the
battery with the engine running. 12.6 volts is the static battery voltage with the engine off.
13. Which component converts mechanical energy from the engine into electrical
energy to charge the battery?
A. Battery
B. Starter motor
C. Alternator
D. Distributor
Answer: C. The alternator converts mechanical energy from the engine (via the drive belt)
into electrical energy to charge the battery and power electrical systems.
14. The vibration damper on an engine is also known as a:
A. Harmonic balancer
B. Flywheel
C. Flexplate
D. Pulley
Answer: A. The vibration damper is also called a harmonic balancer. It absorbs torsional
vibrations from the crankshaft to prevent fatigue failure.
15. Hydrocarbons (HC) in exhaust emissions are primarily caused by:
A. High combustion temperature
B. Lean air-fuel mixture
C. Misfire
D. Open EGR valve
