The system in your hybrid electric vehicle (HEV) is typically a complex integration of a traditional internal combustion engine (ICE) and electronic propulsion. So when you’re driving your hybrid and a hybrid system indicator light comes on, it can leave you with some serious questions.
Read on to learn the answers to that question and more — we’ll cover what forms hybrid warning lights may take, what can cause them, and what to do if yours is illuminated.
What Does “Hybrid System Warning Light” Mean?
Your hybrid system warning light is essentially a “check engine” light for the electrical portion of your hybrid vehicle. This light can take many forms and may display on your dashboard as:
- Hybrid system malfunction
- Check hybrid system
- Hybrid battery warning
In some cars, the color of the light may indicate the severity of the problem, with yellow correlating to a minor issue, and red to a serious one. However, not all hybrid vehicles are the same, and neither are their indicator lights. Always refer to your owner's manual for more guidance.
Can You Continue Driving When the Hybrid System Warning Light Is On?
You may be physically able to continue driving after this warning light comes on, but you probably shouldn’t. Driving when there is an issue with your hybrid’s electrical components can result in:
- Only the combustion engine powering your vehicle, which may reduce fuel economy and acceleration.
- The activation of “limp mode,” where your vehicle’s speed, acceleration, and gearing are restricted.
- Damage to your vehicle’s battery and other components.
When this light comes on, it’s generally safest to pull into the nearest parking lot or a safe spot off the road and have your vehicle towed to a professional who can diagnose the issue.
Potential Culprits of a Hybrid System Warning Light
The hybrid system warning light can come on for various reasons — it could be due to something simple like a blown fuse, or something less benign, like a failed inverter. Here are some common reasons why this type of warning light illuminates:
- Blown fuse(s): Hybrid vehicles use high-voltage fuses to protect important components like your high-voltage battery pack and electrical motors. Age, use, and electrical malfunction can cause these fuses to fail. If they do, your hybrid system warning light may come on. Depending on what part the fuse was connected to, it may also cause your hybrid to run solely on combustion power.
- Faulty high-voltage battery: Like fully electric vehicles, hybrids power their electric motors via a large, high-voltage battery. While these hybrid battery packs can last a long time, nothing lasts forever in the face of use and time. If you’ve noticed that no matter how much regenerative braking you do, your battery simply doesn’t hold a charge like it used to — this could be the culprit of your hybrid system warning or hybrid battery warning light.
- Bad 12-volt battery: In addition to the high voltage battery, your hybrid uses a 12V battery like those found in standard ICE vehicles to start its engine. When these batteries get close to their expiration date or are low on charge, errors that cause the hybrid system warning light can occur. Charging or jumpstarting your hybrid vehicle may resolve the issue.
- Inverter problems: Your hybrid’s inverter is responsible for converting the direct current (DC) stored in the battery to alternating current (AC) that powers the electric motor(s). A failing inverter can reduce your vehicle’s power and cause its hybrid system warning light to illuminate.
What to Do When the Hybrid System Malfunction Light Appears
We’re all about the hard-working DIY crowd, so this is where we would normally break down how to check hybrid battery condition, replace blown fuses, and more. However, due to the complexity of HEVs, repair on the high-voltage system requires specialized diagnostic tools, safety protection, and expertise. Our best advice? This is a task best left to the professionals.
Don't ignore that hybrid system warning light! Firestone Complete Auto Care offers battery repair, fluid and filter replacements, routine checkups, and more for your hybrid! Contact your nearest storefront to ensure these services are available in your area. Our professional technicians will take a look and help you get to the bottom of the issue. Schedule an appointment today.
