Hybrid vehicles are equipped with an electric motor and a combustion engine like a traditional vehicle. Hybrid vehicles offer the best of both worlds, using the combustion engine for long range and regenerative braking for increased efficiency in the city.
Although hybrid vehicles offer significant advantages over vehicles equipped solely with a combustion engine or an electric powertrain, they can encounter problems like any other technology.
One such problem is the “check hybrid system” warning light. Here are some tips for troubleshooting this issue.
What Does “Check Hybrid System” Mean?
The Check Hybrid System warning indicates that a fault has been detected in the vehicle’s hybrid system. This fault could be related to the battery, a computer managing the hybrid system, or the electric motor.
This message is typically found on the Toyota Prius, but it can also appear on other hybrid vehicles. Sometimes, the problem is as simple as a blown fuse. The warning is usually accompanied by a check engine light.
Causes of the Check Hybrid System Warning
1) Faulty Hybrid Battery
Batteries age over time. They hold less charge and eventually stop working. If you own an older Prius or another hybrid vehicle, it’s highly likely that your hybrid battery will need to be replaced at some point.
Although this is a fairly expensive repair at the mechanic, ChrisFix offers an excellent video on YouTube showing how to replace the hybrid battery yourself if it’s something you’d be comfortable doing.
2) Faulty 12V Battery
The 12V battery is a standard car battery and is not specific to hybrid vehicles. Sometimes, a problem with the 12V battery can trigger a Check Hybrid System warning.
If you suspect your 12V battery is faulty, replacing it is quite straightforward. Some auto parts stores may offer a service to do this for you, but it’s also easy for many people to do themselves.
3) Bad Inverter
An inverter converts the direct current from the hybrid battery into alternating current for the electric motor(s). When your inverter fails, your vehicle will no longer be able to properly supply electrical power to the wheels.
4) Wiring Problem
Hybrid systems are equipped with more electrical components, which means more wiring and grounding points. A broken wire or a bad ground can trigger a warning light or render the hybrid system unusable.
To search for a faulty wire, it’s always best to have a manufacturer-provided wiring diagram on hand. Some vehicles may be prone to corrosion or poor wiring in certain areas. When rodents get into your vehicle, they sometimes chew on wires, which can also cause faults and error codes.
5) Blown Fuse
A blown fuse is the simplest and cheapest fix for a warning light. So always check for blown fuses when troubleshooting an issue. Most fuse boxes are located either in the vehicle’s floor area or under the hood.
Can You Drive with the “Check Hybrid System” Message?
There are many cases where your car stalls while driving and fails to start with the gasoline engine alone when you see this message. In this case, you may need to address the root cause of the problem or at least reset the warning to get your vehicle started again.
If your car is operating normally, you can often continue driving safely even with the light on. Of course, this will depend on the exact cause of the problem.
If you have doubts about your vehicle’s safety, it’s always best to take it to a qualified mechanic. Sometimes, they can perform a quick diagnostic to assess the vehicle’s roadworthiness.
How to Reset the Check Hybrid System Warning
Turn off the vehicle, lift the hood, and open the trunk. You will find the hybrid battery in the trunk, near the spare wheel. On the hybrid battery, there is an orange safety switch. Remove it by sliding the handle towards the left side of the vehicle, then pulling it outward.
Next, go to the hood and open the fuse box. You should see a large wire with a white connector at the end. Disconnect the white connector from the fuse box.
Wait 10 minutes with both components disconnected, then reinstall them in the reverse order. Turn the engine on and off 3 times. This should make the warning light disappear in many cases. If your warning light did not turn off, you may have a more permanent issue with your battery or hybrid system.
Note that this does not necessarily fix the root cause of your problem. So don’t be surprised if the warning light comes back on in the future. The Check Hybrid System light can come on because you have a battery that is still working intermittently but is about to fail.