Download ASE T5 Practice Questions – Electronics & Electrical Systems and more Exams Health sciences in PDF only on Docsity!
ASE T5 Practice Questions – Electronics & Electrical Systems
1. Which of the following can cause a battery to discharge when the vehicle is off? (Select all that apply) A. A parasitic draw from a faulty relay B. A loose battery cable C. Leaving a dome light on D. Faulty alternator Correct Answers: A, C Explanation: A parasitic draw or leaving lights on can discharge the battery. A loose cable may prevent starting but doesn’t cause discharge; a faulty alternator affects charging while the engine runs. 2. When diagnosing a vehicle that has intermittent starting issues, which steps are appropriate? (Select all that apply) A. Check battery voltage B. Inspect starter relay and connections C. Replace the starter without testing D. Test ignition switch Correct Answers: A, B, D Explanation: Intermittent starting problems require checking voltage, relays, and ignition switch operation. Replacing parts without testing is not best practice. 3. Which of the following are common causes of an alternator undercharging? (Select all that apply) A. Loose serpentine belt B. Broken alternator diode C. Low engine oil D. Corroded battery terminals Correct Answers: A, B, D Explanation: Mechanical belt issues, internal alternator diode failure, or poor connections can cause undercharging. Low engine oil does not affect charging. 4. Which electrical components use a ground connection? (Select all that apply) A. Headlights B. Fuel pump C. Ignition coil D. Transmission filter
Correct Answers: A, B, C Explanation: Most electrical components require a ground to complete the circuit. Transmission filter is mechanical and unrelated to electrical grounds.
5. Symptoms of a failing crankshaft position sensor can include: (Select all that apply) A. Engine misfire B. No-start condition C. Poor fuel economy D. Low coolant level Correct Answers: A, B, C Explanation: The crankshaft sensor affects ignition timing and fuel injection; a low coolant level is unrelated. 6. When using a scan tool, which data can help diagnose charging system problems? (Select all that apply) A. Battery voltage at idle and load B. Alternator output current C. Engine oil temperature D. Charging system voltage regulation Correct Answers: A, B, D Explanation: Scan tools provide voltage, current, and regulation data; oil temperature is unrelated to electrical diagnosis. 7. Which of the following can cause a short to ground? (Select all that apply) A. Chafed wiring harness B. Wet connector C. Blown fuse D. Metal object contacting wire insulation Correct Answers: A, B, D Explanation: Short circuits occur when wires contact ground through damage, moisture, or foreign objects. A blown fuse is a symptom, not a cause. 8. In a CAN bus network, what can cause communication errors? (Select all that apply) A. Faulty ECU B. Damaged wiring or connectors C. Weak battery D. Dirty air filter
B. Battery C. Starter motor D. Voltage regulator Correct Answers: A, B, D Explanation: Alternator generates power, battery stores it, and voltage regulator controls output. Starter uses power but is not part of the charging system.
13. Common symptoms of a failing oxygen sensor include: (Select all that apply) A. Poor fuel economy B. Rough idle C. Engine overheating D. Check Engine light on Correct Answers: A, B, D Explanation: Faulty O2 sensors affect fuel mixture, triggering rough idle, poor economy, and diagnostic codes. Overheating is unrelated. 14. Which are acceptable methods for checking a parasitic battery drain? (Select all that apply) A. Using a digital multimeter in series B. Disconnecting the battery to see if it drains C. Removing fuses one by one while measuring current D. Jump-starting the vehicle repeatedly Correct Answers: A, C Explanation: Proper methods involve measuring current draw. Simply disconnecting or jump-starting does not identify the source. 15. Which conditions can cause a vehicle’s ECU to go into “limp mode”? (Select all that apply) A. Throttle position sensor failure B. Engine overheating C. Mass airflow sensor failure D. Dirty cabin air filter Correct Answers: A, B, C Explanation: Critical sensor failures or engine conditions can force limp mode to protect the engine. Cabin air filters do not affect ECU operation. 16. Which of the following can result in voltage drop in a starting circuit? (Select all that apply)
A. Corroded battery terminals B. Loose ground connection C. Long, low-gauge wires D. Faulty windshield wipers Correct Answers: A, B, C Explanation: Poor connections or undersized wiring cause voltage drops. Wipers are unrelated.
17. When troubleshooting a hybrid vehicle battery, which tests are appropriate? (Select all that apply) A. Measure individual cell voltage B. Perform insulation resistance test C. Check coolant level for battery pack D. Measure brake pad thickness Correct Answers: A, B, C Explanation: Hybrid batteries require electrical and thermal checks. Brake pads are unrelated to battery diagnostics. 18. Which of the following can trigger false codes in a vehicle’s OBD-II system? (Select all that apply) A. Loose gas cap B. Low transmission fluid C. Faulty wiring harness D. Dirty air filter Correct Answers: A, C Explanation: Loose caps or wiring problems can trigger codes. Low fluid or dirty air filter may cause performance issues but usually do not generate codes. 19. Which of these tests are used to evaluate a starter motor? (Select all that apply) A. Voltage drop test across starter B. Current draw test C. Insulation resistance test D. Compression test Correct Answers: A, B Explanation: Voltage and current tests reveal starter health. Insulation testing is for wiring; compression test is for engine cylinders.
24. Which of the following can interfere with a vehicle’s CAN bus network? (Select all that apply) A. Damaged wiring or connectors B. Corroded ECU pins C. Weak battery voltage D. Low transmission fluid Correct Answers: A, B, C Explanation: CAN bus relies on proper connections and voltage. Low transmission fluid does not affect electronic communication. 25. Which of the following components are commonly checked when diagnosing a no- start condition? (Select all that apply) A. Battery voltage B. Starter relay C. Ignition switch D. Brake pads Correct Answers: A, B, C Explanation: No-start diagnostics focus on electrical and ignition components. Brake pads are unrelated. 26. Which of the following can cause intermittent wiper operation? (Select all that apply) A. Faulty wiper motor B. Loose wiring C. Blown fuse D. Low windshield washer fluid Correct Answers: A, B, C Explanation: Electrical issues or motor faults can make wipers intermittent. Washer fluid only affects cleaning, not operation. 27. Causes of poor fuel economy due to electrical problems include: (Select all that apply) A. Faulty oxygen sensor B. Malfunctioning mass airflow sensor C. Loose battery cable D. Faulty crankshaft position sensor
Correct Answers: A, B, D Explanation: Sensors affecting fuel delivery or timing can reduce efficiency. Loose battery cable affects starting, not fuel economy directly.
28. Which of the following can cause a starter to crank slowly? (Select all that apply) A. Weak battery B. Corroded battery terminals C. Faulty alternator D. Low engine oil Correct Answers: A, B, C Explanation: Low voltage from battery, poor connections, or charging issues cause slow cranking. Engine oil has minimal effect unless extremely low and affecting mechanical drag. 29. Which of the following are considered high-voltage components in hybrid/electric vehicles? (Select all that apply) A. Traction battery pack B. Inverter/converter C. Electric motor D. Headlight relay Correct Answers: A, B, C Explanation: Traction battery, inverter, and motor handle high voltage. Headlight relay is low voltage. 30. Common causes of a blown fusible link include: (Select all that apply) A. Short circuit B. High current draw C. Loose connections D. Low coolant level Correct Answers: A, B, C Explanation: Fusible links protect circuits from shorts and overloads. Low coolant is unrelated. 31. Which of the following can trigger a Check Engine light? (Select all that apply) A. Malfunctioning EGR valve B. Oxygen sensor failure C. Low windshield washer fluid D. Loose gas cap
Correct Answers: A, B, D Explanation: Coil failure causes misfire, hard starting, and poor efficiency. Engine not cranking is usually battery/starter related.
36. Which of the following can cause a parasitic battery drain? (Select all that apply) A. Faulty relay stuck closed B. Dome lights left on C. Short in wiring D. Dirty air filter Correct Answers: A, B, C Explanation: Electrical issues and lights can drain the battery. Air filters do not consume electrical power. 37. Which are proper tests for diagnosing a faulty alternator? (Select all that apply) A. Voltage test at battery with engine running B. Check for AC ripple at battery C. Measure resistance of battery terminals D. Compression test Correct Answers: A, B Explanation: Alternator diagnosis includes voltage and ripple tests. Terminal resistance and compression test are not used. 38. Which of the following can cause intermittent power to accessories? (Select all that apply) A. Loose ground connections B. Faulty ignition switch C. Blown fuse D. Dirty cabin air filter Correct Answers: A, B, C Explanation: Power issues often come from grounds, switches, or fuses. Cabin air filter is unrelated. 39. Which of the following can trigger a battery warning light while driving? (Select all that apply) A. Broken alternator belt B. Faulty voltage regulator C. Low engine oil D. Corroded battery terminals
Correct Answers: A, B, D Explanation: Belt, regulator, and terminal issues affect charging. Low oil does not trigger battery light.
40. Common causes of engine misfire include: (Select all that apply) A. Faulty spark plug B. Failing ignition coil C. Vacuum leak D. Low windshield washer fluid Correct Answers: A, B, C Explanation: Misfires result from ignition, fuel, or vacuum problems. Washer fluid is unrelated.
ASE T5 Practice Questions 41– 60
41. Which of the following can cause headlights to flicker while idling? (Select all that apply) A. Weak battery B. Loose alternator belt C. Faulty alternator D. Low brake fluid Correct Answers: A, B, C Explanation: Low voltage at idle from a weak battery, slipping belt, or alternator problem causes flicker. Brake fluid is unrelated. 42. When performing a voltage drop test on a starter circuit, which areas should be tested? (Select all that apply) A. Battery positive to starter terminal B. Battery negative to engine block ground C. Starter solenoid to ignition switch D. Spark plug gap Correct Answers: A, B Explanation: Voltage drop tests check positive and ground paths to the starter. Spark plug gap is unrelated. 43. Which of the following can trigger a P0300 OBD-II code? (Select all that apply) A. Misfiring cylinder B. Faulty ignition coil
B. Remove fuses one at a time to locate draw C. Jump-start the vehicle repeatedly D. Disconnect battery and check voltage over time Correct Answers: A, B Explanation: Proper diagnosis measures current draw; disconnecting battery or repeated jump-starts is ineffective.
48. Which of the following can cause a battery to discharge rapidly? (Select all that apply) A. Dome lights left on B. Faulty alternator diode C. Shorted relay D. Low engine coolant Correct Answers: A, B, C Explanation: Lights, alternator faults, or shorted relays draw current. Low coolant does not. 49. Which of the following tests can detect a failing alternator diode? (Select all that apply) A. AC voltage test at battery B. Ohmmeter test across diodes C. DC voltage test at battery with engine off D. Fuel pressure test Correct Answers: A, B Explanation: AC ripple indicates diode failure; direct diode continuity check confirms it. DC voltage and fuel pressure are unrelated. 50. Which of the following can cause a high resistance in a wiring circuit? (Select all that apply) A. Corroded terminals B. Loose connections C. Damaged insulation D. Low engine oil Correct Answers: A, B, C Explanation: Resistance increases from corrosion, loose connections, or damaged wires. Oil does not affect electrical resistance. 51. Which of the following components are part of a vehicle’s starting system? (Select all that apply)
A. Starter motor B. Ignition switch C. Battery D. Alternator Correct Answers: A, B, C Explanation: Starter, switch, and battery work together to crank the engine. Alternator is part of the charging system, not starting.
52. Symptoms of a faulty mass airflow sensor include: (Select all that apply) A. Poor acceleration B. Check Engine light on C. Rough idle D. Blown fuse Correct Answers: A, B, C Explanation: MAF sensor issues affect engine air/fuel mixture, causing hesitation, rough idle, and codes. Fuses are usually unaffected. 53. Which of the following can cause intermittent instrument cluster operation? (Select all that apply) A. Loose ground wires B. Faulty instrument cluster C. Blown fuse D. Low engine oil Correct Answers: A, B, C Explanation: Electrical issues or faulty cluster can cause intermittent gauges. Oil level is unrelated. 54. Which of the following can cause a vehicle’s ABS system to fail? (Select all that apply) A. Faulty wheel speed sensor B. Open ABS fuse C. Low brake fluid D. Faulty windshield wiper motor Correct Answers: A, B, C Explanation: Sensors, fuses, and fluid level are critical to ABS function. Wipers do not affect ABS.
59. Which of the following can cause a vehicle to fail to start intermittently? (Select all that apply) A. Faulty ignition switch B. Loose battery cable C. Faulty crankshaft position sensor D. Low windshield washer fluid Correct Answers: A, B, C Explanation: Electrical and sensor issues affect starting; washer fluid is unrelated. 60. Which of the following tests can help diagnose a slow-cranking starter? (Select all that apply) A. Battery voltage measurement B. Voltage drop test across starter circuit C. Compression test D. Current draw test Correct Answers: A, B, D Explanation: Battery health, voltage drop, and starter current indicate starter performance. Compression test is for engine mechanical condition. We’re now at 60 questions. Next, I can continue with 61 – 80 to keep moving steadily toward
Shall I continue with 61–80? countinue Perfect! Let’s continue with ASE T5 practice questions 61– 80 , maintaining the multiple- answer format with correct answers and explanations.
ASE T5 Practice Questions 61– 80
61. Which of the following can cause a parasitic battery drain? (Select all that apply) A. Interior lights left on B. Faulty relay stuck closed C. Shorted wiring harness D. Low coolant level Correct Answers: A, B, C Explanation: Battery drains occur from lights left on, stuck relays, or shorts. Coolant level does not draw electrical power.
62. Which of the following are common symptoms of a failing alternator? (Select all that apply) A. Battery warning light on B. Dim headlights C. Engine stalling D. Engine oil light on Correct Answers: A, B, C Explanation: Alternator failure causes low voltage symptoms. Oil light relates to oil pressure, not charging. 63. Which of the following can cause a blown fuse repeatedly? (Select all that apply) A. Short to ground in the circuit B. Overloaded circuit C. Loose battery connection D. Faulty relay Correct Answers: A, B, D Explanation: Shorts, overloads, and relay failure can blow fuses. Loose battery connections affect starting, not fuse integrity. 64. Which of the following are proper methods to test a starter motor? (Select all that apply) A. Voltage drop test across starter circuit B. Current draw test C. Insulation resistance test D. Compression test Correct Answers: A, B Explanation: Starter diagnosis involves voltage drop and current testing. Compression test is for engine cylinders; insulation test is for wiring. 65. Which of the following can trigger a Check Engine light? (Select all that apply) A. Faulty oxygen sensor B. Loose gas cap C. Dirty air filter D. Malfunctioning EGR valve Correct Answers: A, B, D Explanation: Sensors and emissions system problems or loose gas caps trigger codes. Air filter alone does not.
70. Which of the following can cause a slow-cranking starter? (Select all that apply) A. Weak battery B. Loose or corroded battery terminals C. Faulty alternator D. Low engine oil Correct Answers: A, B, C Explanation: Low voltage due to weak battery, poor connections, or charging issues causes slow cranking. Engine oil is not a primary factor. 71. Which of the following are considered high-voltage components in hybrid/electric vehicles? (Select all that apply) A. Traction battery pack B. Electric motor C. Inverter/converter D. Headlight relay Correct Answers: A, B, C Explanation: Only battery pack, motor, and inverter handle high voltage. Headlight relay is low voltage. 72. Which of the following can cause ABS system failure? (Select all that apply) A. Faulty wheel speed sensor B. Open ABS fuse C. Low brake fluid D. Faulty windshield wiper motor Correct Answers: A, B, C Explanation: Sensors, fuses, and brake fluid are critical to ABS function. Wipers do not affect ABS. 73. Which of the following can cause a blown fusible link? (Select all that apply) A. Short circuit B. High current draw C. Loose connections D. Low engine oil Correct Answers: A, B, C Explanation: Fusible links protect circuits from overcurrent or shorts. Oil is unrelated. 74. Which of the following tests can help identify a failing alternator diode? (Select all that apply)
A. AC voltage test at battery B. Ohmmeter test across diode bridge C. DC voltage test at battery with engine off D. Fuel pressure test Correct Answers: A, B Explanation: AC ripple and diode continuity tests identify bad diodes. DC voltage alone and fuel tests are unrelated.
75. Which of the following can cause intermittent starting issues? (Select all that apply) A. Faulty ignition switch B. Loose battery cable C. Faulty crankshaft position sensor D. Low windshield washer fluid Correct Answers: A, B, C Explanation: Electrical or sensor faults affect starting; washer fluid is unrelated. 76. Which of the following are proper steps when diagnosing a parasitic draw? (Select all that apply) A. Connect multimeter in series with battery B. Remove fuses one at a time to locate the circuit C. Jump-start the vehicle repeatedly D. Disconnect battery and check voltage over time Correct Answers: A, B Explanation: Proper methods involve measuring current draw; repeated jump-starts or battery disconnection do not locate the draw. 77. Which of the following can cause engine misfire? (Select all that apply) A. Faulty spark plug B. Failing ignition coil C. Vacuum leak D. Low windshield washer fluid Correct Answers: A, B, C Explanation: Misfires are caused by ignition or air/fuel delivery issues. Washer fluid is unrelated. 78. Which of the following can cause a blown fuse repeatedly? (Select all that apply) A. Short circuit in the circuit B. Overloaded circuit
