ASE Light Duty Hybrid/Electric Vehicle 2 — Questions and Answers
Question 1: Before disconnecting a high-voltage battery, what is the FIRST safety step a technician should take?
- Remove the high-voltage service disconnect/manual service disconnect (MSD) (Correct answer)
- Drain the coolant
- Disconnect the 12V auxiliary battery only
- Spray the terminals with dielectric grease
Correct answer: Remove the high-voltage service disconnect/manual service disconnect (MSD)
Removing the manual service disconnect isolates the high-voltage battery pack into safe, non-lethal segments before any service.
Question 2: What color are high-voltage cables typically marked on a hybrid or electric vehicle?
- Orange (Correct answer)
- Green
- Blue
- Yellow
Correct answer: Orange
Orange insulation is the industry standard marking for high-voltage (50V or higher) wiring and cables.
Question 3: Which type of personal protective equipment is essential when handling exposed high-voltage components?
- Class 0 insulated lineman's gloves (Correct answer)
- Standard leather work gloves
- Cotton gloves
- Latex examination gloves
Correct answer: Class 0 insulated lineman's gloves
Class 0 rubber insulating gloves are rated to 1000V and protect technicians from electric shock during HV service.
Question 4: After de-energizing a high-voltage system, how long should a technician typically wait before touching components?
- At least 5–10 minutes for capacitors to discharge (Correct answer)
- Immediately, no wait is required
- 24 hours
- 30 seconds
Correct answer: At least 5–10 minutes for capacitors to discharge
A waiting period of several minutes allows inverter and converter capacitors to fully discharge their stored energy.
Question 5: Which instrument should be used to verify that a high-voltage circuit is de-energized?
- A CAT III rated digital multimeter (Correct answer)
- A 12V test light
- An analog dwell meter
- A non-contact voltage pen only
Correct answer: A CAT III rated digital multimeter
A properly rated (CAT III/IV) multimeter safely measures high voltage to confirm the circuit reads zero volts.
Question 6: What does an illuminated 'READY' indicator on a hybrid dashboard signify?
- The vehicle can move even though the engine may be silent (Correct answer)
- The engine has stalled
- The 12V battery is dead
- The car is in park lock
Correct answer: The vehicle can move even though the engine may be silent
The READY light means the hybrid system is energized and the vehicle can move under electric power without engine sound.
Question 7: What is the purpose of the orange safety loop/interlock circuit on the high-voltage harness?
- To automatically de-energize the HV system if a connector is opened (Correct answer)
- To boost charging speed
- To regulate cabin temperature
- To dim the headlights
Correct answer: To automatically de-energize the HV system if a connector is opened
The high-voltage interlock loop (HVIL) signals the system to shut down power if any HV connector is disconnected.
ASE Light Duty Hybrid/Electric Vehicle 2
Before disconnecting a high-voltage battery, what is the FIRST safety step a technician should take?