Four Types of EMI Issues OEMs Should Know About

What is Electromagnetic Interference?

J.W. Speaker - EMI - Lighting Education

Electromagnetic Interference (EMI) refers to a disturbance that affects an electrical circuit. Lights can both cause and be the victim of EMI issues in your vehicle. For this reason, it is important to have a basic understanding of standard EMI format and to look for headlights that have been adequately designed and tested to reduce electromagnetic interference.

Four Types of EMI

There are four main types of EMI that you should be aware of:
  • Radiated Emissions: Electromagnetic noise emitted through the air that can interfere with other electronics (ex. cell phone, radio, etc.)
  • Conducted Emissions: Electromagnetic noise conducted down a power line in a vehicle which can interfere with other electronic components in the vehicle.
  • Radiated Immunity: The tolerance of a light to inbound electromagnetic noise in the atmosphere. Any broadcast signal (cell phone, radio tower, etc.) can interfere with a headlight if it is not properly designed.
  • Conducted Immunity: The tolerance of a light to inbound electromagnetic noise conducted on vehicle power lines.

Component Level vs. Vehicle Level

For OEM applications, lighting manufacturers focus on testing their products at a component (light) level. This is done to make sure that the headlights lights will not cause a vehicle-level EMI failure or interfere with other electronics in the vehicle. OEMs then test at a vehicle level to ensure that it meets regulatory requirements.

Standard vs. Custom Products

At J.W. Speaker, we design and manufacture both standard and custom products. For our standard products, we’ve established a set of high standards by which we design and test for electromagnetic compliance. For custom products, we design, test, and manufacture to meet your exact specifications. If you do not have EMI specifications, we’ll provide you with a list of industrial EMI standards to review and approve before we start on the design.

EMI Testing Capabilities

J.W. Speaker has EMI testing equipment on-site at our production facility which enables us to do the following:

SAE J1455

  • Load Dump (Pulse 5) (J1113/11)
  • Inductive Switching (Pulse 1/2) (J1113/11)
  • Burst Transients (Pulse 3a/3b) (J1113/11)
  • Starter Motor Engagement (Pulse 4) (J1113/11)
  • Electrical Fast Transients (J1113/12)
  • Chattering Relay (J1113/12)
  • Radiated Emissions (J1113-41)
  • Conducted Emissions, DC Power Leads (J1113-41)

EN 12895 Industrial Trucks Electromagnetic Compatibility

  • EN 55022 With Exception of the Antenna Height
  • CISPR 12
  • CISPR 22
  • CISPR 25
  • Mil STD — 461F (Army Mobile Emissions ONLY)

SAE J2139

  • Load Dump
  • Inductive Switching
  • Mutual

ECE Reg. 10

  • Broadband Electromagnetic Emissions
  • Narrowband Electromagnetic Emissions
  • Immunity: ISO11452-4
  • ISO 7637-2 Pulses 1, 2a, 2b, 3a, 3b, 4
  • ISO 7637-2 Emission of Conducted Disturbances


  • SAE J1113-13 (SAE J1455)
  • ISO 10605
  • IEC 61000-4-2 (EN 12895)

Want more information on Electromagnetic Interference

If you have specific questions about electromagnetic interference or how our lights comply with EMI standards, contact us at 1-800-558-7288 or

About J.W. Speaker

J.W. Speaker is focused on developing innovative, high-performance vehicular lighting solutions for OEM and aftermarket customers around the world. Specialized in LED and other emerging lighting technologies, J.W. Speaker is proud to design, manufacture and assemble products in Germantown, Wisc. For more information, contact J.W. Speaker at (800) 558-7288 or

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