Toyota hybrids are some of the most reliable cars on the road, but when something goes wrong the dashboard can light up in ways a petrol car never does. Some lights mean "book it in this week". A few mean "stop now". Here is how to tell them apart on a Prius and on most Toyota and Lexus hybrids.
The red triangle (master warning)
A red triangle with an exclamation mark is the master warning light. On its own it does not tell you what is wrong: it tells you to read the message on the screen next to it. The message is what matters, so note it down or take a photo before you turn the car off.
"Check Hybrid System"
This message means the hybrid control system has found a fault and stored a code. Sometimes the car carries on almost normally. Sometimes it limits power, and on some models you will see a small turtle symbol, which means the system is protecting itself by reducing the power available.
The cause can be the hybrid battery, the inverter or its cooling, a sensor or a fault elsewhere that the hybrid system has picked up. It is not automatically the battery, and it should not be "fixed" by clearing the code and hoping. A proper diagnosis reads the code and the live data behind it.
- Car drives normally: book a diagnosis soon and avoid long journeys until then.
- Power reduced, turtle symbol, or the car will not go: stop somewhere safe and call us. We can collect the car.
The engine warning light
The amber engine-shaped light means the engine management system has found a fault, often to do with emissions, sensors or the way the engine runs. On a hybrid the cause can also sit in the hybrid system, so it is worth having the codes read by someone with hybrid equipment. Note that a lit engine warning light is an MOT fail.
Brake, ABS and stability warnings
Hybrids use a brake system that blends regenerative braking with the normal brakes. Warnings about the brakes, ABS or stability control should be taken seriously. If the pedal feels different, longer or harder than usual, stop driving and call us.
The car will not go "READY"
If the dashboard lights come on but the car will not show "READY", the most common cause is a weak 12V auxiliary battery, not the hybrid battery. Hybrids can be jump-started on their 12V system; your handbook shows where the jump point is. If the 12V battery is several years old, it is often simply time to replace it.
Fuel economy dropping and the engine running more
This is not a light, but it is often the first sign of a tired hybrid battery: the engine starts more often, the car drives less on electric power and the economy falls. A battery health check measures every module and tells you whether that is the cause or whether it is something simpler, like tyres or a dragging brake.
What to do next
- Note the exact message and which lights are on.
- If the car has lost power, the brakes feel wrong or a red warning will not go out, stop safely.
- Book a diagnosis. We read the codes and the live data, tell you what we found and agree the price before any work.