What is the triangle exclamation point light on my Toyota Sienna?

The triangle-with-exclamation light on a Toyota Sienna is the Master Warning indicator. It signals a general fault in one or more of the vehicle’s systems and you should check the car’s information display for the exact message.

In practice, it can come on for a wide range of issues—from doors not fully closed or a low fuel level to a fault in the braking, stability control, or other critical systems. The light is amber (yellow), indicating caution rather than an emergency, but you should not ignore it.

What the symbol means

The warning is known as the Master Warning. It’s designed to catch your attention and prompt you to read the message shown on the instrument cluster or multi-information display. The light itself does not tell you which system is at fault; the accompanying text will.

Distinguishing master warning from other lights

In Toyota dashboards, a red warning light for brake, airbag, or engine indicates a more urgent problem, while the amber triangle indicates a general caution. Treat it as something you should check soon, but not necessarily an emergency unless it is accompanied by other red warnings or a specific urgent message.

Common causes you might see with the Sienna

Here are some frequent triggers for the Master Warning light on the Sienna, though the exact cause will be shown in the display.

• Messages on the instrument cluster such as “Open door,” “Check tire pressure,” or “Check fuel level.”


• Low fuel level or fuel system issues indicated by a related message.


• Brake system or vehicle stability control faults detected by the ECU.


• Other miscellaneous system faults flagged by the vehicle’s computer (engine, transmission, airbags, etc.).

Because the Master Warning is a catch‑all, the exact next step depends on the message shown in the display. Most issues are actionable, but some faults require professional diagnosis to ensure ongoing safety and reliability.

What to do when the light comes on

Follow these steps to assess and address the issue safely and efficiently.

1. Note the exact message or icon shown on the instrument cluster or multi-information display to identify the specific system affected.


2. Check for obvious, quick-fix issues: ensure all doors and the tailgate are closed properly, check the fuel level, and verify tires are inflated to the recommended pressures if a tire-related message appears.


3. If the display indicates a system fault or the light remains after addressing obvious issues, drive cautiously to a service center for a diagnostic scan.


4. If you notice reduced braking performance, longer stop distance, or other unsafe symptoms, slow down, pull over safely, and seek assistance or tow the vehicle to a repair facility.


5. Have the vehicle scanned with a Toyota-compatible OBD-II tool or at a dealership to retrieve trouble codes and identify the fault.

In most cases, a Master Warning can be resolved after a simple fix or a reset, but some faults require professional inspection to ensure ongoing safety and reliability.

When to seek immediate service

Urgent service is warranted if the Master Warning appears with a red brake warning light, an airbag warning, or if you feel noticeable changes in braking, steering, or engine behavior. If you’re unsure, stop in a safe location and contact roadside assistance or a Toyota service center.

Summary

The triangle exclamation point on your Toyota Sienna signals a Master Warning—a general alert that a fault has been detected in one or more systems. Read the message on the dashboard to identify the specific issue, address obvious quick fixes, and seek professional diagnosis if the warning persists or if safety-related systems are involved. Regular maintenance and timely diagnostics help prevent unexpected alerts and keep your Sienna running safely.

What does the exclamation mark mean on my Toyota Sienna?

A Toyota Sienna's exclamation point light has two main meanings: a yellow, horseshoe-shaped light indicates low tire pressure (TPMS), while a yellow triangle with an exclamation point is a master warning light for a general system fault. The TPMS light requires you to check your tire pressure and inflate to the correct PSI; if the light stays on, a leak is possible. The master warning light requires you to check your vehicle's information display for a specific message, as it signifies a more general issue that needs attention. 
You can watch this video to learn how to reset the maintenance warning light on a Toyota Sienna: 1mDaniel Puccetti the Mec ManYouTube · Jul 3, 2024
Yellow, horseshoe-shaped exclamation point light 

• What it means: Your tire pressure is low in one or more tires. This could be due to a leak or a significant drop in temperature.
• What to do:
  • Check the pressure of all your tires (including the spare if applicable) as soon as possible and inflate them to the recommended PSI.
  • The correct pressure can be found on a sticker in the driver's side door jamb.
  • If the light stays on after inflating, there may be a slow leak, and you should have the tires inspected by a technician. 

Yellow triangle with an exclamation point

• What it means: A general warning that a fault has been detected in a system that requires your attention. A buzzer may also sound. 
• What to do:
  • Look at your vehicle's information display on the dashboard for a more specific message. 
  • Common causes include a loose fuel cap or other maintenance alerts. 
  • If the message indicates a more serious issue, follow the recommended action or have a technician check it promptly. 

You can watch this video to see what the warning light looks like and what it means: 55sSteven WelchYouTube · Sep 21, 2020

Is it safe to drive with a triangle warning light on?

A yellow triangle with an exclamation point is usually a non-critical warning. It indicates that the problem you're dealing with won't necessarily put you in danger while you're on the road, but you should still have your vehicle checked.

What does a triangle with an exclamation mark mean on my Toyota?

The yellow triangle with an exclamation point in a Toyota is the Master Warning Light, which signifies a general malfunction or alert that requires your attention. It indicates that another, more specific warning is displayed on the multi-information display (MID) and you should check the display to determine the exact problem. This could be a range of issues, from a low tire pressure warning to a more serious problem with the Vehicle Stability Control (VSC) or power steering system.
 
This video explains the meaning of the yellow triangle with an exclamation mark and what to do when you see it: 1mAutomobile Garage HubYouTube · Jun 4, 2025
Common meanings and actions

• Check the multi-information display: The first step is to check the message center on your dashboard for a more specific warning. This light often serves as a catch-all for issues that other lights don't cover. 
• Service Reminder: The light can sometimes indicate that scheduled maintenance is due. 
• Tire Pressure Warning: This can be triggered by low tire pressure, which is a relatively simple fix, as noted in this Toyota Camry dashboard lights guide. 
• Vehicle Stability Control (VSC)/Traction Control Malfunction: The light can indicate a problem with your VSC or traction control system. 
• Power Steering System Malfunction: A yellow light next to a steering wheel indicates a problem with the power steering, making it more difficult to steer. 
• Other Malfunctions: The light could also be related to other issues, such as a problem with the Anti-Lock Braking System (ABS), which is a crucial safety feature, explains this article from Auburn Toyota. 

What you should do

• Check the message center: As soon as it is safe to do so, check the display on your dashboard for a more specific message. 
• Consult your owner's manual: Your owner's manual will provide details specific to your vehicle's model. 
• Take it to a professional: If the specific warning indicates a serious problem, such as an issue with the braking or power steering system, it is best to have the vehicle inspected by a qualified technician as soon as possible. 

What is the master warning ⚠?

The master warning light, a triangle with an exclamation mark, is a general warning that indicates a malfunction in one or more of the vehicle's safety or advanced electronic systems. It can signal issues ranging from low windshield washer fluid to serious problems with the engine, brakes, or stability control. When this light appears, you should check the car's display for a specific message and consult the owner's manual to identify the exact problem and determine if it is safe to drive.
 
This video explains what the master warning light means and what actions you should take: 20sToyota of SeattleYouTube · May 3, 2018
Possible causes

• Low fluid levels: Windshield washer fluid, brake fluid, or oil can be a common trigger. 
• System malfunctions: It can indicate a problem with advanced systems like the electronic stability control, anti-lock brakes, or power steering. 
• Sensor issues: Faulty sensors related to various systems can also trigger the light. 
• Routine maintenance needed: It can simply be a reminder that a scheduled service is due. 

You can watch this video to learn more about the causes of the master warning light, such as low washer fluid and open doors: 41sMotor MatchupsYouTube · Dec 21, 2024
What to do

1. Check your display: Look at the car's information display for a more specific message that often accompanies the master warning light. 
2. Consult the owner's manual: The manual will provide a guide to all dashboard symbols and explain what the master warning light means for your specific vehicle model. 
3. Check basic fluid levels: If there are no other obvious messages, check your windshield washer fluid, and then your brake fluid. 
4. Do not ignore it: Even if it turns out to be a minor issue, like low washer fluid, it's important to address the cause to turn the light off and prevent future issues. 
5. Seek professional help: If you cannot determine the cause or if the light indicates a serious problem, it is best to have your car inspected by a qualified mechanic. 

This video shows how to diagnose and reset the master warning light: 1mDashboard warning lights YouTube · Aug 6, 2025