Yanmar ViO55-6A Warning Lights and Symbols (Meaning and Fixes)

The Yanmar ViO55-6A is a compact excavator powered by a 54.8 hp Yanmar diesel engine and a robust hydraulic system. Its instrument cluster uses color-coded warning lights to alert the operator to machine status, ensuring safe and efficient operation on job sites.

How to read the colors: Red indicators demand immediate attention and shutdown; amber warns of required maintenance or caution; green or blue shows active systems or normal operation.

Yanmar ViO55-6A Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDThis red stop symbol appears when a critical fault is detected, such as engine overheating or low oil pressure, requiring immediate shutdown on your ViO55-6A.Stop the engine immediately, consult the error code on the display, and contact your Yanmar dealer.
Master CautionAMBERAn amber caution light illuminates for non-critical issues like a clogged air filter or pending maintenance on the ViO55-6A, warning you to plan service soon.Check the display for associated messages and schedule service at your earliest convenience.
Check Engine (MIL)AMBERThis light signals an emission or engine control system fault specific to the ViO55-6A's Yanmar diesel engine, often due to sensor errors or fuel quality.Reduce engine load and have the diagnostic codes read by a qualified technician.
Engine Oil PressureREDLow oil pressure detected in the ViO55-6A's engine, which can be caused by low oil level or a malfunctioning oil pump, risking severe engine damage.Stop the engine, check oil level, and add oil if low; if the light persists, do not restart and seek service.
Battery / ChargingREDThe alternator is not charging the battery on your ViO55-6A, often due to a loose belt or failed alternator, leading to electrical system failure.Check the alternator belt tension and battery connections; if tight, have the charging system tested.
Coolant TemperatureREDEngine coolant temperature is above safe limits on the ViO55-6A, typically from radiator blockage or low coolant level, risking overheating.Stop the engine, let it cool, then check coolant level and radiator fins for debris.
Low FuelAMBERThe fuel level in the ViO55-6A's tank is low, which can cause air ingestion and engine stalling if ignored.Refill the fuel tank as soon as possible to avoid running dry.
Glow Plug / PreheatAMBERThis indicator shows the preheat cycle is active on the ViO55-6A's diesel engine; it typically goes off when the engine is ready to start.Wait for the light to turn off before cranking the engine.
Hydraulic OilREDHigh hydraulic oil temperature or low hydraulic oil level in the ViO55-6A, which can degrade performance and damage hydraulic components.Check hydraulic oil level and ensure the cooling fan is operating; allow the system to cool before resuming work.
Work LightsGREENGreen indicator confirms the work lights are turned on for visibility during low-light operations on the ViO55-6A.No action needed; lights are active.
Beacon / Rotating LightGREENThis green light indicates the rotating beacon is active, improving machine visibility for safety on the ViO55-6A.No action required; beacon is functioning.
Swing / Slew LockAMBERThe swing lock is engaged on the ViO55-6A to prevent the upper structure from rotating during transport or service.Release the swing lock before operating the excavator.
Service / Hour MeterAMBERThe hour meter indicates scheduled maintenance is due based on engine operation hours on the ViO55-6A.Perform the required service as per the maintenance interval in the operator's manual.
Air FilterAMBERRestricted air flow from a clogged air filter on the ViO55-6A, which can reduce engine power and increase fuel consumption.Inspect and replace the air filter element if dirty.
Water in FuelAMBERWater has accumulated in the fuel filter/water separator of the ViO55-6A, which can cause injector damage and poor performance.Drain the water from the fuel filter bowl immediately.

15 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.

Most Important Warning Lights

Engine Overheating

Common causes

  • Low coolant level
  • Clogged radiator or debris on fins
  • Faulty thermostat

What to do

Stop the ViO55-6A and let the engine cool. Check coolant level and radiator cleanliness. If the problem persists, inspect the fan belt and thermostat; consult your Yanmar dealer.

Hydraulic System Overheat

Common causes

  • Low hydraulic oil level
  • Plugged hydraulic oil cooler
  • Excessive load or continuous operation

What to do

Allow the ViO55-6A to idle to cool down, check hydraulic oil level and cleanliness. Clean the oil cooler fins and reduce continuous heavy load operation.

Low Engine Oil Pressure

Common causes

  • Low oil level
  • Worn oil pump or clogged filter
  • Diluted or incorrect oil viscosity

What to do

Immediately stop the engine on your ViO55-6A. Check oil level; if adequate, have the oil pressure sensor and pump inspected by a technician before restarting.

Charging System Failure

Common causes

  • Loose or broken alternator belt
  • Failed alternator
  • Corroded battery terminals

What to do

Check the alternator belt tension and condition on the ViO55-6A. Clean battery terminals and connections. If the light remains, have the alternator tested and replaced if necessary.

Fuel System Water Contamination

Common causes

  • Water in fuel tank
  • Clogged water separator
  • Biodiesel phase separation

What to do

Drain the fuel/water separator on the ViO55-6A. If water reappears, drain the fuel tank and refill with clean diesel. Replace the fuel filter if needed.

Frequently Asked Questions

What does the red stop light on my Yanmar ViO55-6A mean?

The red stop light indicates a critical fault like low oil pressure or high coolant temperature. You should stop the engine immediately and consult the digital display for the specific error code.

How do I reset the service hour meter on the ViO55-6A?

The service hour meter resets automatically after completing the required maintenance and using the dealer diagnostic tool. There is no user reset; follow the maintenance schedule in your manual.

Why is the amber caution light on with no other indicator?

An amber caution alone often signals a pending maintenance item, such as an upcoming service or a minor sensor reading. Check the multi-function display for a message or code.

Can I operate the excavator with the swing lock light on?

No, the swing lock light means the upper structure is locked. Operating with it engaged can damage the slew mechanism. Release the lock before digging.

How often should I change the hydraulic oil on the ViO55-6A?

Yanmar recommends changing the hydraulic oil every 1000 hours or annually, whichever comes first. Refer to your operator's manual for exact intervals and oil specifications.

What should I do if the check engine light comes on while digging?

Reduce engine load and complete the current task if safe. Have the diagnostic codes read as soon as possible; the ViO55-6A may enter limp mode to protect the engine.