Toyota Prius ZVW30 warning lights: what each one means
16 warning lights and 18 multi-information display messages from Toyota's own owner's manual, grouped by how urgently the manufacturer says to act, with the printed page or original web section for each so you can check the original.
Japan-market Prius ZVW30 as covered by the May 2010 manual edition. Later editions and export-market manuals may differ. Lights marked equipment-dependent are fitted only on some grades.
A warning light is the car reporting a condition, not a diagnosis of a specific part. If braking, steering or engine behaviour changes, stop where it is safe. If you are unsure, follow the manual and contact a dealer. This page does not replace a professional inspection.
The manufacturer says to stop somewhere safe straight away, or to stop if specific symptoms occur.
Brake warning lightStop safely now
Manual name: ブレーキ警告灯 · red · printed p.402
When it lights
Low brake fluid or a brake-system fault (with a warning buzzer for hydraulic or electrical faults).
Also lit while the parking brake is applied; if it goes out once released, that is normal. A buzzer sounds if the car is driven above about 5 km/h with the parking brake on.
What the manual says to do
Toyota says a brake failure is possible: stop in a safe place immediately and contact a Toyota dealer. Continuing to drive is dangerous.
If the parking brake is applied, release it.
Toyota notes that a light which comes on and then goes out is not a fault, but the car should be inspected if the same thing happens again.
Charging warning lightStop safely now
Manual name: 充電警告灯 · printed p.403
When it lights
A fault in the charging system.
What the manual says to do
Stop in a safe place immediately and contact a Toyota dealer.
High coolant temperature warning lightStop safely now
Manual name: 高水温警告灯 · printed p.403, 458
When it lights
Abnormal petrol-engine coolant temperature.
What the manual says to do
Stop in a safe place immediately and contact a Toyota dealer; the manual's overheating procedure is on p.458.
Low engine oil pressure messageStop safely now
Manual name: エンジンオイル圧力の異常 · printed p.408
When it lights
Engine oil pressure is abnormally low; shown on the multi-information display with a buzzer and the master warning light.
What the manual says to do
Stop in a safe place immediately and contact a Toyota dealer.
Have it inspected promptly
The manufacturer says to have the car inspected by a dealer promptly.
Check engine warning lightHave it inspected promptly
Manual name: エンジン警告灯 · printed p.404
When it lights
A fault in the engine electronic control system, the hybrid system or the electronic throttle.
What the manual says to do
Have the car inspected by a Toyota dealer immediately.
Hybrid system malfunction messageHave it inspected promptly
Manual name: ハイブリッドシステムの異常 · printed p.409
When it lights
A hybrid-system fault, shown on the multi-information display with a buzzer.
What the manual says to do
Have the car inspected by a Toyota dealer immediately.
Electronically controlled brake warning lightHave it inspected promptly
Manual name: 電子制御ブレーキ警告灯 · yellow · printed p.404
When it lights
A fault in the electronically controlled brake system or the regenerative braking system.
What the manual says to do
Have the car inspected by a Toyota dealer immediately.
ABS & brake assist warning lightHave it inspected promptly
Manual name: ABS＆ブレーキアシスト警告灯 · printed p.404
When it lights
A fault in ABS or brake assist.
What the manual says to do
Have the car inspected by a Toyota dealer immediately.
Power steering warning lightHave it inspected promptly
Manual name: パワーステアリング警告灯 · printed p.404–405
When it lights
A fault in the electric power steering.
It can also light if the auxiliary (12V) battery is undercharged or its voltage drops briefly.
What the manual says to do
Steering may become very heavy: hold the wheel firmly and steer with more force than usual.
Have the car inspected by a Toyota dealer immediately.
Slip indicatorHave it inspected promptly
Manual name: スリップ表示灯 · printed p.404
When it lights
Flashing: S-VSC, TRC or hill-start assist is working (normal).
On: a fault in S-VSC, TRC or hill-start assist control.
What the manual says to do
If it stays on, have the car inspected by a Toyota dealer immediately.
SRS airbag / pretensioner warning lightHave it inspected promptly
A fault in the SRS airbag or pretensioner seat-belt system.
What the manual says to do
Have the car inspected by a Toyota dealer immediately.
P position control system messageHave it inspected promptly
Manual name: P ポジション制御システムの異常 · printed p.409
When it lights
A fault in the P (park) position control system, with a buzzer.
What the manual says to do
The parking lock may not work: park on level ground and apply the parking brake firmly.
If the power switch will not turn off, apply the parking brake and it can then be switched off.
Have the car inspected by a Toyota dealer immediately.
Pre-crash safety (PCS) warning lightHave it inspected promptly
Manual name: PCS 警告灯 · printed p.404 · fitted on some grades only
When it lights
A pre-crash safety system fault.
Flashes quickly while the system operates; lit when pre-crash braking is switched off or the system is temporarily unavailable.
What the manual says to do
For a fault, have the car inspected by a Toyota dealer immediately.
Check and correct
Often caused by something you can check or correct yourself; see the conditions listed.
Low fuel warningCheck and correct
Manual name: 燃料残量警告灯 · printed p.406
When it lights
About 6 L or less of fuel remains; a buzzer sounds and the lowest fuel-gauge segment flashes.
What the manual says to do
Refuel.
Door ajar warning lightCheck and correct
Manual name: 半ドア警告灯 · printed p.406
When it lights
A door is not fully closed; a buzzer sounds above about 5 km/h.
What the manual says to do
Close the open door.
Seat belt remindersCheck and correct
Manual name: シートベルト非着用警告灯 · printed p.406–407
When it lights
The driver or front passenger seat belt is unfastened (buzzer above about 20 km/h).
Luggage on the passenger seat can trigger the passenger reminder; a seat cushion can stop it detecting a passenger.
What the manual says to do
Fasten the seat belt.
Multi-information display messages
When the master warning light comes on, the display shows a message. Most messages on this car are pictorial or Japanese, so each entry gives the manual's own description in Japanese, an English translation of that description and Toyota's response. The English is a CarFactBook translation, not the exact on-screen wording, unless a quoted display text is shown. If the message reappears after you have followed the response, the manual says to contact a dealer.
Stop safely and contact a dealer
Engine oil pressure abnormal
Manual description: エンジンオイル圧力の異常 · printed p.408
Shown with a buzzer when engine oil pressure is abnormally low.
Toyota: stop in a safe place immediately and contact a Toyota dealer.
Have it inspected immediately
Hybrid system abnormality
Manual description: ハイブリッドシステムの異常 · printed p.409
A buzzer sounds.
Toyota: have the car inspected by a Toyota dealer immediately. The manual does not name a failed component for this message.
EV drive mode cannot be selected in the current conditions
Manual description: EVドライブモードに切りかえできない状況にいる · printed p.413 · fitted on some grades only
A buzzer sounds; a reason may appear on the second line.
Use EV drive mode once conditions allow. This is not a fault message.
Shown when starting the hybrid system
12V auxiliary (starting) battery charge low
Manual description: 補機バッテリーが充電不足 · Display text quoted in the manual: 「補機バッテリー（始動用）充電不足」 · printed p.414
Shown for about 6 seconds at start-up.
If it clears after a few seconds: keep the hybrid system operating for about 15 minutes or more to charge the 12V battery.
If it does not clear: start the hybrid system using the manual's flat 12V battery procedure (printed p.452).
If it appears frequently, Toyota warns the 12V battery may be deteriorating and should be inspected by a dealer. It does not indicate a traction-battery fault.
If the 12V battery low-charge message appears at the next start, follow the printed p.414 response above.
Electronic key battery low
Manual description: 電子キーの電池残量が少ない · printed p.419
Replace the key battery (manual printed p.382). See the linked ZVW30 smart-key battery guide.
Source: Toyota Motor Corporation, Prius owner's manual (Japan), May 2010 edition. Open the original manual ↗ (Japanese). English wording on this page is a CarFactBook paraphrase of the manual, checked on 2026-10-27.
