Komatsu excavators feature a robust instrument cluster that provides real-time feedback on machine health, operation status, and safety conditions. Understanding each warning and indicator light is crucial for maximizing uptime and preventing costly damage during heavy-duty excavation tasks.
Komatsu excavator Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | A critical fault has been detected by the Komatsu excavator’s monitoring system that could result in severe equipment damage or unsafe operation. | Safely park the excavator and shut down the engine immediately; investigate fault code via monitor. | |
| Master Caution | AMBER | A non-critical issue or malfunction has been identified that needs attention but does not require an immediate stop. | Review the display for details; schedule inspection or repair soon. | |
| Check Engine (MIL) | AMBER | The Komatsu excavator's engine control unit has logged a diagnostic fault that could impact performance. | Consult the monitor for error codes and arrange for service. | |
| Engine Oil Pressure | RED | Oil pressure has dropped below the safe range, risking serious engine damage in your Komatsu excavator. | Shut down the engine immediately and check oil level and condition. | |
| Battery / Charging | RED | The alternator is not charging the battery, risking a loss of electrical power during operation. | Stop the engine and inspect the alternator belt and battery terminals. | |
| Coolant Temperature | RED | Coolant temperature has exceeded safe limits, indicating potential overheating in the Komatsu’s engine. | Turn off the engine and allow it to cool; check coolant level and radiator. | |
| Transmission Temp | AMBER | Transmission oil temperature is abnormally high, which can damage transmission components. | Pause work and allow the system to cool; inspect for leaks or low fluid. | |
| Brake System | RED | A malfunction has been detected in the Komatsu excavator’s brake system, affecting stopping capability. | Stop operation and contact maintenance before resuming work. | |
| Parking Brake | RED | The parking brake is engaged, preventing movement of the Komatsu excavator. | Release the parking brake before attempting to travel. | |
| Glow Plug / Preheat | AMBER | The preheat system is active, preparing the Komatsu engine for cold weather starting. | Wait until the light turns off before starting the engine. | |
| DPF / Regeneration | AMBER | The diesel particulate filter is undergoing regeneration or requires regeneration soon. | Allow the regeneration process to complete or initiate manual regen as indicated. | |
| DEF / AdBlue | AMBER | The DEF (AdBlue) fluid level is low or there is a system fault, affecting emissions control. | Refill DEF tank with correct fluid or address DEF system error. | |
| Water in Fuel | AMBER | Water has been detected in the fuel separator, risking injector or engine damage. | Drain water from the fuel water separator promptly. | |
| Low Fuel | AMBER | Fuel level is approaching empty, risking unexpected shutdown during operation. | Refuel the excavator at the next safe opportunity. | |
| High Beam | BLUE | High beam work lights are switched on for enhanced visibility. | Switch off if not needed to conserve battery power. | |
| Hydraulic System | RED | A hydraulic system fault or dangerously low pressure has been detected in your Komatsu excavator. | Stop machine movement, check hydraulic fluid level, and inspect for leaks. | |
| Hydraulic Oil | AMBER | Hydraulic oil level is low or the temperature is above normal operating range. | Top off hydraulic oil or let the system cool before resuming. | |
| Engine Oil Temperature | AMBER | Engine oil temperature is higher than recommended, possibly due to heavy load or cooling issues. | Reduce load and idle engine to lower oil temperature. | |
| Air Filter | AMBER | Air filter is clogged or excessively dirty, reducing engine efficiency. | Clean or replace air filter to restore airflow. | |
| Fuel Filter / Water Separator | AMBER | Fuel filter is restricted or water separator needs attention, risking poor engine performance. | Replace filter or drain water from separator. | |
| Service / Hour Meter | AMBER | Scheduled maintenance interval has been reached according to Komatsu’s hour meter. | Perform recommended maintenance as outlined in the operator’s manual. | |
| Work Lights | GREEN | Work lights are currently illuminated, improving visibility around the Komatsu excavator. | Turn off when not needed to prevent battery drain. | |
| Beacon / Rotating Light | AMBER | The safety beacon is active, signaling machine presence on site. | Ensure beacon is functioning for site safety compliance. | |
| Swing / Slew Lock | AMBER | Swing lock is engaged, preventing upper structure rotation. | Disengage swing lock before rotating the cab. | |
| Overload / Capacity | RED | The excavator is lifting beyond its rated capacity, risking tip-over or structural damage. | Reduce load immediately and ensure operation within rated limits. | |
| Low Oil Level | AMBER | Detected oil level is below the minimum mark, which can cause engine or hydraulic damage. | Check and add the appropriate oil to the specified reservoir. | |
| Door Open | AMBER | One of the cab doors is not fully closed, which may affect safety interlocks. | Close all cab doors securely before operating. | |
| High Exhaust Temp (HEST) | AMBER | Exhaust temperature is elevated, often during DPF regeneration. | Keep area around exhaust clear and avoid shutdown until complete. |
28 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Engine Oil Pressure
Common causes
- Low oil level
- Oil pump failure
- Blocked oil filter
What to do
Shut down the Komatsu excavator immediately, check oil level and quality, and inspect for leaks or replace the oil filter as needed.
Hydraulic System
Common causes
- Hydraulic fluid leak
- Pump malfunction
- Contaminated hydraulic oil
What to do
Stop operation, inspect all hydraulic lines and fittings for leaks, and check fluid level; consult Komatsu service if issue persists.
Coolant Temperature
Common causes
- Low coolant level
- Radiator blockage
- Faulty thermostat
What to do
Allow engine to cool, then check coolant level and radiator for obstructions; refill coolant and replace faulty parts as necessary.
Overload / Capacity
Common causes
- Attempting to lift excessive weight
- Incorrect bucket or attachment
- Unstable ground conditions
What to do
Reduce load to within rated capacity, use appropriate attachments, and ensure the excavator is on stable ground before resuming.
Brake System
Common causes
- Brake fluid leak
- Worn brake pads
- Hydraulic brake failure
What to do
Cease operation, inspect the brake system for leaks or wear, and repair or replace components before using the machine again.
Frequently Asked Questions
What should I do if the DPF regeneration light stays on?
Operate the Komatsu excavator at high idle to allow automatic regeneration, or follow the on-screen instructions for manual regeneration.
How often should I check the hydraulic oil level?
Inspect the hydraulic oil level daily before starting the machine to prevent system damage.
Can I continue working if the DEF/AdBlue light is amber?
You may continue briefly, but refill the DEF tank as soon as possible to avoid power reduction or engine derate.
Why does the air filter light come on even after cleaning?
Persistent air filter warnings may indicate a sensor issue or excessive dust; inspect the filter housing and sensor for blockages.
Is it safe to operate with the swing lock engaged?
No, always disengage the swing lock before rotating the upper structure to avoid damaging the mechanism.