You installed your new LED headlight bulbs, turned them on — and they flicker. Or your dashboard shows a "bulb out" warning even though the lights are clearly on.
Don't worry. This is one of the most common issues with LED headlight upgrades, and it's easy to fix. In most cases, you don't even need to return the bulbs.
This guide explains why LED headlights flicker, which vehicles are most affected, and the three ways to fix it.
Why Do LED Headlights Flicker?
The short answer: your car thinks the bulb is burned out.
Here's what's happening:
Your vehicle's computer system (called CANBUS) monitors how much power each bulb draws. A factory halogen bulb draws 55W. When you replace it with an LED that draws only 20–25W, the computer sees the lower power draw and assumes the bulb has failed.
The result is one or more of these symptoms: - Flickering or strobe effect — the computer rapidly cycles the power on and off - "Bulb out" dashboard warning — the warning light stays on even though the LED is working - One bulb works, the other doesn't — the computer disables the circuit on one side - LEDs turn off after a few seconds — the computer shuts down the circuit entirely
This is not a defect in the LED bulb. It's a compatibility issue between the LED's lower power draw and your vehicle's monitoring system.
Which Vehicles Have This Problem?
Not all vehicles have CANBUS headlight monitoring. Here's the general breakdown:
Most Likely to Flicker
- European vehicles — BMW, Mercedes, Audi, Volkswagen, Volvo, Mini (almost always CANBUS-equipped)
- 2018+ American trucks — Ford F-150, RAM 1500, Chevrolet Silverado (newer model years)
- 2015+ vehicles in general — CANBUS monitoring has become standard on most new cars
Usually No Issues
- Japanese vehicles (pre-2018) — Toyota, Honda, Subaru, Nissan (older models rarely have headlight CANBUS)
- Older American vehicles (pre-2015) — simpler electrical systems
- Motorcycles, ATVs, UTVs — typically no CANBUS
Hard to Predict
- Jeep Wrangler — some model years flicker, others don't
- Hyundai/Kia — varies by trim and year
The only way to know for sure is to try the bulbs. If they flicker, the fix is straightforward.
3 Ways to Fix LED Headlight Flickering
Fix 1: Use LED Bulbs with a Built-in CANBUS Decoder
The simplest solution. Some LED bulbs come with a CANBUS decoder built into the driver circuit. The decoder draws additional power to simulate the electrical signature of a halogen bulb, so the car's computer sees normal power consumption.
Pros: No extra parts, no extra wiring. True plug-and-play. Cons: Slightly higher price. The bulb runs a bit warmer due to the extra power draw.
This is what the Driveon Summit Series does. Every Summit bulb has a built-in CANBUS decoder — no external parts needed. It works on Ford, RAM, GM, and European vehicles without flickering.
Fix 2: Add an External CANBUS Decoder
If your LED bulbs don't have a built-in decoder (like most budget LEDs), you can add an external one. It's a small module that plugs inline between your car's wiring harness and the LED bulb.
How it works: 1. Unplug the LED bulb from the car's harness 2. Plug the decoder into the car's harness 3. Plug the LED bulb into the decoder 4. Secure the decoder with a zip tie (keep it away from hot surfaces)
Pros: Works with any LED bulb. Costs $10–$20 per pair. Cons: Extra wiring. Must be mounted securely. Generates heat (use a metal-body decoder, not plastic).
Fix 3: Add a Load Resistor
A load resistor is the brute-force approach. It adds a resistor in parallel with the LED to increase the total power draw back to halogen levels (55W).
Pros: Cheapest option ($5–$10). Works on virtually any vehicle. Cons: The resistor converts the extra power into heat — a lot of it. Must be mounted on a metal surface away from plastic and wiring. Defeats the energy-saving benefit of LED. Not recommended for enclosed housings.
We don't recommend load resistors. They generate excessive heat and are a fire risk if improperly mounted. A CANBUS decoder is safer and more reliable.
Which Fix Should You Choose?
| Your Situation | Recommended Fix |
|---|---|
| Haven't bought LED bulbs yet | Get bulbs with built-in CANBUS (e.g., Driveon Summit) |
| Already have LEDs that flicker | Add an external CANBUS decoder ($10–$20) |
| Budget is the only concern | Load resistor (not recommended) |
| European vehicle (BMW, VW, etc.) | Built-in CANBUS is strongly recommended |
Coast vs Summit: Which One Won't Flicker?
| Coast Series — $39.99 | Summit Series — $64.99 | |
|---|---|---|
| CANBUS | No built-in decoder | Built-in decoder |
| Flickering | May flicker on 2018+ trucks and European cars | No flickering on any vehicle |
| Best for | Japanese vehicles, older cars, budget upgrade | Trucks, SUVs, European cars, any modern vehicle |
If you're not sure whether your car will flicker: go with the Summit. It eliminates the guesswork.
Frequently Asked Questions
Will LED headlights damage my car's electrical system? No. LED bulbs draw less power than halogen, which actually reduces load on your electrical system. The flickering is just a monitoring issue — it doesn't cause any damage.
Can flickering damage the LED bulb? Prolonged rapid flickering can reduce LED lifespan over time. If your LEDs are flickering, fix it sooner rather than later.
My LEDs worked fine for months, then started flickering. Why? Some vehicles update their monitoring software during dealer visits. A software update can change how aggressively the CANBUS monitors bulb draw. Adding a decoder will fix it.
Do I need one decoder per bulb or one per pair? One per bulb. If both sides flicker, you need two decoders (one for each headlight).
Will a CANBUS decoder work for fog lights too? Yes. The same type of decoder works for headlights, fog lights, and other exterior lighting.
Not sure if your vehicle needs a CANBUS decoder? Contact us with your Year, Make, and Model — we'll tell you which Driveon series is the right fit.