EVT High Voltage Electrical Systems & Wiring 3

Question 1

What is the typical high-voltage bus operating range for a 400V-class battery electric vehicle?

Accepted Answer

300–450V DC

Answer

48–100V DC

Answer

150–250V DC

Answer

600–900V DC

Question 2

After removing the manual service disconnect, why must a technician wait before touching HV components?

Accepted Answer

To allow large bus capacitors to discharge to a safe voltage level through internal bleed resistors

Answer

To allow the BMS to complete its shutdown self-test routine

Answer

To let coolant fully drain from HV cable conduits

Answer

To ensure all software fault codes are automatically cleared

Question 3

What does an isolation fault code in an EV high-voltage system indicate?

Accepted Answer

An unintended electrical path exists between the HV circuit and the vehicle chassis

Answer

The battery pack has insufficient charge to operate the vehicle

Answer

A cell voltage imbalance has been detected in the battery pack

Answer

The charging inlet connector is not properly seated

Question 4

What does applying a lockout/tagout (LOTO) procedure during EV high-voltage service ensure?

Accepted Answer

The HV system cannot be accidentally re-energized while a technician is working on it

Answer

It prevents the vehicle from being moved to another service bay

Answer

It records battery state of health in the dealership service database

Answer

It prevents software updates from being applied during active repair

Question 5

Which tool provides a non-contact method of confirming HV absence on EV cables before making direct contact?

Accepted Answer

Non-contact high-voltage tester rated for the system voltage

Answer

Standard automotive test light rated for 12V

Answer

Analog ohmmeter with standard test leads

Answer

OBD-II diagnostic scan tool

Question 6

When routing high-voltage wiring near heat sources in a hybrid vehicle, what is the primary safety concern?

Accepted Answer

Heat degradation of cable insulation leading to potential isolation failure

Answer

Increased EMI interference with vehicle electronics

Answer

Reduced cable current-carrying capacity due to elevated ambient temperature only

Answer

Color fading of the orange jacket reducing visual identification

Question 7

What is the correct method for repairing a damaged high-voltage cable in an EV when a manufacturer-approved procedure exists?

Accepted Answer

Manufacturer-approved HV splice kit that restores shielding continuity and rated insulation

Answer

Standard automotive crimp connectors with electrical tape wrap

Answer

Soldering the conductors and wrapping with standard electrical tape

Answer

Any weatherproof automotive connector rated for the circuit current