Komatsu PC240 Warning Light Symbols and What They Mean

The Komatsu PC240 is a mid-sized hydraulic excavator widely used in construction and earthmoving. Its instrument cluster provides essential alerts and status updates to ensure safe and efficient operation. Understanding each indicator is crucial for minimizing downtime and preventing costly repairs.

How to read the colors: Red lights indicate immediate hazards or failures requiring you to stop operation. Amber signals a caution or maintenance issue that needs attention soon, while green or blue lights show normal operation or activated features.

Komatsu PC240 Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDA major system fault has been detected on the PC240, such as severe engine or hydraulic failure.Shut down the machine immediately and investigate the cause.
Master CautionAMBERA non-critical system issue or parameter out of range has been detected by the PC240's monitoring system.Check the monitor for detailed messages and address the issue soon.
Check Engine (MIL)AMBERThe engine control system on your PC240 has detected a malfunction.Consult the diagnostic menu and schedule service.
Engine Oil PressureREDEngine oil pressure has dropped dangerously low, risking severe damage.Stop the engine as soon as safely possible and check oil level.
Battery / ChargingREDThe charging system is not functioning and your PC240 is running on battery power.Inspect alternator and battery connections before continuing.
Coolant TemperatureREDEngine coolant temperature has exceeded safe limits on the PC240.Stop work, idle engine, and inspect coolant level and radiator.
Hydraulic SystemREDA hydraulic fault or severe loss of pressure has been detected.Cease operation and inspect hydraulic oil level and system.
Hydraulic OilAMBERHydraulic oil level is low or oil temperature is abnormal in the PC240.Check hydraulic oil reservoir and add fluid if necessary.
Low FuelAMBERFuel level is nearing empty, risking unexpected shutdown.Refuel at the next opportunity.
DPF / RegenerationAMBERThe diesel particulate filter in your PC240 requires regeneration.Allow automatic or perform manual regeneration as instructed.
DEF / AdBlueAMBERDEF/AdBlue level is low, which may limit performance soon.Top up DEF/AdBlue tank to avoid engine derate.
Water in FuelAMBERWater has been detected in the fuel system, risking injector damage.Drain water separator promptly.
Fuel Filter / Water SeparatorAMBERThe fuel filter is clogged or water separator needs service.Replace the fuel filter or drain separator soon.
Air FilterAMBERAir filter restriction is detected, impacting engine efficiency.Inspect and clean or replace the air filter.
Engine Oil TemperatureREDEngine oil temperature is excessively high, risking engine damage.Idle the engine to cool, then check oil and cooling system.
ATTransmission TempREDTransmission oil temperature has reached a critical level.Stop operation and allow transmission to cool.
Service / Hour MeterAMBERScheduled maintenance interval reached based on engine hours.Perform required service as per Komatsu PC240 schedule.
Work LightsBLUEWork lights are currently switched on for the PC240.Turn off when not needed to conserve battery.
Beacon / Rotating LightBLUEThe beacon light is active, signaling machine presence.Use when working in active or low-visibility areas.
PParking BrakeREDParking brake is engaged, preventing machine movement.Release brake before attempting to move the PC240.
Swing / Slew LockAMBERThe swing lock is engaged, restricting upper structure rotation.Disengage swing lock before rotating the upper frame.
Overload / CapacityREDLift capacity has been exceeded, risking machine stability.Lower the load immediately and reassess lifting plan.
Door OpenAMBERCab or service door is not fully closed on the PC240.Secure all doors before resuming operation.

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

Most Important Warning Lights

Low Engine Oil Pressure

Common causes

  • Low oil level
  • Oil pump failure
  • Blocked oil filter

What to do

Stop the PC240, check and top up oil, and inspect for leaks or damaged components before restarting.

High Coolant Temperature

Common causes

  • Low coolant level
  • Radiator blockage
  • Cooling fan malfunction

What to do

Idle the engine, inspect coolant level and radiator, and clean or repair as needed before continuing.

Hydraulic System Failure

Common causes

  • Hydraulic oil leak
  • Clogged hydraulic filter
  • Pump or valve malfunction

What to do

Shut down the PC240, check for visible leaks, inspect filters, and call for service if the problem persists.

Overload Condition

Common causes

  • Lifting load beyond rated capacity
  • Incorrect attachment use
  • Uneven ground conditions

What to do

Lower the load, review machine limits in the PC240 manual, and ensure proper setup before lifting again.

DEF/AdBlue Depletion

Common causes

  • DEF tank empty
  • DEF pump failure
  • Contaminated DEF fluid

What to do

Refill the DEF tank with clean fluid and check for system faults; continued operation without DEF may result in engine derate.

Frequently Asked Questions

What should I do if the DPF regeneration light stays on?

Follow the on-screen instructions to perform a parked or manual regeneration on your PC240; if the light persists, contact Komatsu service.

Can I operate the PC240 with the master caution light on?

You may continue working briefly, but check the monitor for details and address any issues promptly to avoid escalation.

Why does the hydraulic oil light keep flashing?

Check the hydraulic oil level and temperature; continued flashing may indicate a leak or filter issue.

How do I reset the service interval after maintenance?

Use the PC240 monitor panel to access the service menu and follow prompts to reset the hour meter.

What happens if I ignore the DEF/AdBlue warning?

Ignoring the DEF/AdBlue warning will eventually cause the PC240 to enter reduced power mode, limiting performance until the tank is refilled.