High Voltage Vehicle Safety Systems

This four-part course from SAE training partner FutureTech* is most beneficial if completed before servicing hybrid, plug-in and electric vehicles. These vehicles contain high voltage DC and AC safety systems that are monitored by vehicle systems controllers that will maintain a safety barrier between the vehicle operator and the vehicle body/chassis to mitigate the possibility of electrical shock. This presentation will provide the technical information and background to know how these systems operate and affect vehicle operation and driveability.

At the conclusion of this series, you will be equipped to describe the operation of vehicle high voltage safety systems, how to test them, why they can cause a no-start condition, and how to test the system with special tools and scan tools to identify isolation fault areas for practical application. Ford, GM, Honda, Lexus, Toyota and other popular products are featured.

What Will You Learn

By participating in this on-demand course, you'll be able to:

  • Identify High Voltage systems by color code
  • Recognize the construction and operation of Manual Disconnect systems
  • Know the location of the Manual Disconnect
  • Describe the operation of High Voltage Manual Disconnect systems
  • Identify Interlock Safety systems used on High Voltage systems by using circuit diagrams
  • Describe the operation of High Voltage Interlock systems

Course Information

4.50 Hours
90 Days

Is This Course For You

The design and implementation of high voltage vehicle safety systems is a requirement for Engineers that develop vehicle electrification products. Engineers with limited or some knowledge of high voltage vehicle electrification systems, or those that need to update their current knowledge or just need a good refresher, will benefit.

*FutureTech develops and delivers comprehensive Vehicle Electrification solutions that include technical training, specialty diagnostic equipment and, professional support services to automotive service professionals. Its highly qualified network of suppliers, affiliations and, partners encompasses over 32 years of commercial experience focused in Vehicle Electrification education and technology development.

Materials Provided

  • 90 days of online single-user access (from date of purchase)  to the four hour presentation
  • Online learning assessment
  • Course handbook (downloadable, .pdf's)
  • Instructor follow up to your content questions
  • 0.4 CEUs*/Certificate of Achievement (upon completion of all course content and a score of 70% or higher on the learning assessment)

*SAE International is authorized by IACET to offer CEUs for this course.

Course Requirements

  • Windows or macOS
  • Microsoft Edge, Mozilla Firefox, Google Chrome, Safari (Other OSs and browsers including mobile devices are not supported by may work)
  • Broadband-1Mbps minimum


Part 1:  Manual Disconnect and High Voltage Interlock Systems

  • High Voltage Cables and Wire (Orange)
  • Service/Manual Disconnect Systems
  • High Voltage Interlock Systems
  • Active & Passive High Voltage Bus Discharge Systems
  • High Voltage Isolation Fault Systems
  • Collision Detections and High Voltage Systems

Part 2:  High Voltage Isolation Fault Systems

  • Vehicle Safety System Requirements (FMVSS 305)
  •  Purpose of Isolation Fault Detection Circuits
  •  Vehicle Isolation Fault System & Operation
    • DC Isolation Fault Detection Circuit
    • AC Isolation Fault Detection Circuit
  •   Diagnosing Isolation Faults using Scan Tool and Insulation Tool

Part 3:  Active and Passive Bus Discharge Systems

  • Purpose and Location of HV Bus Discharge Systems
  • Circuit Operation of Active Passive Bus Discharge Systems
  • Testing the Active & Passive Bus Discharge Circuits

Part 4:  Insulation Meter Testing of High Voltage Components

  • Active Discharge Operation & Voltage Testing
  • Isolation Faults and Associated DTCs are Common Faults in HV Automotive Systems
    • Insulation Testing is required to locate Isolation Fault
    •  Isolation Fault results in a Loss of Propulsion 
  •  Use Vehicle Systems to help locate the Isolation Fault
  •  Use Insulation Meter to Confirm the Fault 

Recommended Content

Professional Development High Voltage Safety and PPE
Professional Development Introduction to Hybrid Electric Vehicle Systems
Professional Development Nickel Metal Hydride (NiMH) Hybrid Battery Systems