Volvo MC135C Warning Lights and Symbols (Meaning and Fixes)

The Volvo MC135C skid steer loader features a comprehensive instrument cluster designed to keep you informed about machine status. Warning and indicator lights use a color-coded system: red indicates immediate action, amber signals caution, and green/blue confirms normal operation.

How to read the colors: Red lights require immediate shutdown or urgent action; amber lights advise prompt inspection; green and blue lights indicate active systems or normal operation.

Volvo MC135C Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDCritical system fault detected: engine, hydraulic, or drivetrain issue requires immediate stop.Stop the MC135C safely, turn off engine, and consult the operator's manual.
Master CautionAMBERNon-critical fault or maintenance reminder active on the MC135C.Check info display for details and address within the next few hours.
Check Engine (MIL)AMBEREngine emissions or performance fault detected on the Volvo D3.8 engine.Have engine diagnosed by authorized Volvo service center.
Engine Oil PressureREDLow engine oil pressure: may cause severe engine damage in the MC135C.Stop engine immediately, check oil level and pressure sensor.
Battery / ChargingREDAlternator not charging or battery voltage low on this loader.Check battery connections, alternator belt, and charge battery.
Coolant TemperatureREDEngine coolant overheating – possible fan, pump, or blockage issue in the MC135C.Stop engine, let cool, check coolant level and radiator fins.
Hydraulic SystemREDHydraulic system pressure or temperature outside safe range on the MC135C.Stop loader, check hydraulic fluid level and look for leaks.
Low FuelAMBERFuel level low – about 10% remaining in the 27-gallon tank.Refuel with diesel as soon as possible to avoid air in system.
Glow Plug / PreheatAMBERPreheat plugs active; wait until light turns off before cranking the engine.Turn ignition to preheat position and wait for light to extinguish.
Seat BeltAMBEROperator seat belt not fastened – safety interlock may limit travel.Fasten seat belt before operating the MC135C.
PParking BrakeREDParking brake engaged or not fully released on the MC135C.Disengage parking brake before moving; if light remains, check brake system.
High BeamBLUEHigh beam headlights are activated on the loader.Dim high beams when approaching other equipment.
Work LightsGREENWork lights are turned on for increased visibility at night.Turn off when not needed to conserve battery.
DPF / RegenerationAMBERDiesel particulate filter is in regeneration to clean soot buildup.Keep engine running at normal operating temperature until regen completes.
Water in FuelAMBERWater detected in the fuel/water separator of the MC135C.Drain water from the separator bowl immediately.
Air FilterAMBEREngine air filter restriction high – service indicator may be tripped.Replace or clean air filter per maintenance schedule.
Hydraulic OilAMBERHydraulic oil level low or temperature approaching limit on the MC135C.Check hydraulic oil level and look for leaks; allow cooling if hot.
Service / Hour MeterAMBERService interval reminder – next maintenance due soon based on engine hours.Schedule service as per operator's manual (e.g., oil change, filters).
Reduced Power (Limp Mode)AMBEREngine power limited due to fault – safe operation but reduced performance.Reduce load and have the MC135C inspected at nearest dealership.

19 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
  • Radiator blockage
  • Failed cooling fan

What to do

Stop the MC135C immediately, check coolant level after engine cools, clean radiator fins and test fan operation. If persistent, contact Volvo service.

Hydraulic System Failure

Common causes

  • Low hydraulic oil
  • Contaminated oil
  • Pump wear

What to do

Park the loader, lower attachments, shut off engine. Check hydraulic fluid level and look for leaks. Replace filters if dirty. If problem persists, have system diagnosed by a technician.

Engine Won't Start

Common causes

  • Low battery voltage
  • Glow plug failure
  • Fuel system air

What to do

Check battery voltage and connections; wait for glow plug light to extinguish before cranking. If fuel-related, prime fuel system by operating hand pump (refer to manual).

Transmission Not Responding

Common causes

  • Low transmission fluid
  • Parking brake engaged
  • Faulty sensor

What to do

Ensure parking brake is released. Check transmission fluid level (dipstick near engine). If light remains, do not force travel; tow to service center.

Regeneration Stuck

Common causes

  • Frequent short cycles
  • Exhaust temperature too low
  • DPF sensor error

What to do

Drive the MC135C at moderate load for 20-30 minutes to allow passive regen. If active regen fails, visit dealer for forced regeneration or DPF cleaning.

Frequently Asked Questions

Why is the master warning light on with no other indicators?

On the MC135C, the master warning can activate for a communication fault. Check the info display for a code and contact Volvo support.

What does the amber hydraulic light mean?

It indicates either low hydraulic oil level or high temperature. Check the sight gauge on the hydraulic tank and let the machine cool down if hot.

How often should I replace the fuel filter?

Volvo recommends replacing the fuel filter and water separator every 500 hours or annually, whichever comes first.

The DPF regen light stays on for over an hour – what should I do?

If the light stays on longer than normal, the regen may be interrupted. Drive the loader at higher load for 30 minutes; if it persists, a forced regen at the dealership is needed.

Can I ignore the seatbelt light if I'm moving slowly?

No, the MC135C's safety interlock may limit travel speed and other functions. Always fasten the seatbelt before operating.

Why does the battery light come on only when idling?

Low alternator output at idle is common. Check the belt tension and battery connections. If it persists, the alternator may need replacement.