Hino Warning Lights and Symbols: Complete Guide

The Hino semi truck instrument cluster provides essential warnings and indicators tailored to its diesel engine and heavy-duty systems. Designed for reliability, it alerts the driver to critical issues like brake air pressure, DEF levels, and DPF regeneration status. Understanding these lights ensures safe operation and prevents costly downtime.

How to read the colors: Red lights demand immediate attention — stop the truck safely. Amber indicates a caution that needs prompt service, while green or blue signals that a system is active or operating normally.

Hino semi truck Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDA critical fault has been detected, often related to brakes, engine, or air pressure, requiring an immediate stop on your Hino.Safely pull over, shut off engine, and consult the warning message on the display.
Master CautionAMBERA non-critical system issue has been logged — check the information display for details specific to your Hino truck.Monitor the gauge cluster and schedule service at your earliest convenience.
Check Engine (MIL)AMBERThe engine control unit has detected an emission or performance fault that could affect Hino's selective catalytic reduction system.Have the diagnostic trouble codes read by a Hino dealer to prevent derate.
Engine Oil PressureREDOil pressure has dropped below safe operating levels — continued operation may damage the J08 or A09 engine in your Hino.Stop engine immediately and check oil level; if okay, call for service.
Battery / ChargingREDThe alternator is not charging the battery properly, which can lead to electrical failure on your Hino truck.Check alternator belt and battery connections; replace battery if necessary.
Coolant TemperatureREDEngine coolant is overheating — this can cause severe gasket failure in the Hino's heavy-duty diesel.Pull over, idle engine briefly, then shut down and check coolant level after cooling.
ATTransmission TempAMBERTransmission fluid is overheating, common when hauling heavy loads in mountainous terrain with your Hino.Reduce speed or shift to a lower gear; if light persists, stop and allow transmission to cool.
Brake SystemREDA brake fault is detected, possibly low air pressure (below 60 psi) or a hydraulic issue on your Hino air brake system.Stop the truck safely — do not drive until brake pressure is restored.
ABSABSAMBERThe anti-lock braking system has a fault; standard brakes still work but traction control may be compromised on your Hino.Have the ABS system diagnosed by a Hino technician soon.
PParking BrakeREDThe parking brake is engaged or not fully released — ensure the yellow knob is pushed in before moving your Hino.Release the parking brake and verify the light extinguishes.
Tire Pressure (TPMS)AMBEROne or more tires on your Hino are significantly underinflated, increasing blowout risk and fuel consumption.Check tire pressures at the nearest safe stop and inflate to recommended psi.
Airbag (SRS)REDThe supplemental restraint system has a malfunction — airbags may not deploy in a collision in your Hino.Visit a Hino service center to inspect the SRS system immediately.
Seat BeltREDDriver or passenger seat belt is unbuckled while the vehicle is in motion on your Hino.Buckle up immediately.
Glow Plug / PreheatAMBERThe glow plugs are heating the intake air for cold starts — wait until the light goes out before cranking your Hino's engine.Turn key to ON, wait for light to extinguish, then start engine.
DPF / RegenerationAMBERThe diesel particulate filter is actively regenerating to burn off soot — continued highway driving is recommended for your Hino.If flashing, drive at highway speeds to complete regen; steady means normal regen.
DEF / AdBlueAMBERDiesel exhaust fluid level is low or quality is poor — without DEF, your Hino's engine will derate and eventually stop.Refill with approved DEF at the next stop; if light stays on, check DEF quality.
Water in FuelAMBERWater has accumulated in the fuel filter/water separator — this can damage the Hino's high-pressure injection system.Drain the water separator on the fuel filter housing.
Low FuelAMBERFuel level is low on your Hino — plan to refuel soon to avoid running out and air in the system.Refuel as soon as possible.
High BeamBLUEHigh beam headlights are activated to improve visibility on dark roads in your Hino.Dim when approaching oncoming traffic.
Power Steering (EPS)REDElectric power steering system failure — steering will become very heavy in your Hino.Stop the truck safely and have the EPS system inspected.
AIRAir Brake Pressure (Low)REDAir pressure in the brake system is below 60 psi — brakes may not apply fully on your Hino truck.Stop immediately and allow air compressor to build pressure; if it doesn't, call for service.
EBEngine / Exhaust BrakeGREENThe engine or exhaust brake is active — it assists braking on downgrades in your Hino.No action needed; deactivate if not required.
TrailerAMBERTrailer ABS fault detected through the 7-pin connector — trailer brakes may not be optimized on your Hino.Check trailer ABS connection and have trailer serviced.
Door OpenREDA cab door is open or not securely closed on your Hino.Check and close all doors securely.
High Exhaust Temp (HEST)AMBERExhaust system temperature is high, often during DPF regeneration — avoid parking over dry grass with your Hino.Continue driving or park in a safe area until temperature drops.
Washer Fluid LowAMBERWindshield washer fluid level is low — visibility may be reduced on your Hino.Refill the washer fluid reservoir.

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

Most Important Warning Lights

Air Brake Failure

Common causes

  • Air compressor malfunction
  • Leak in air lines
  • Faulty brake valve

What to do

Stop the Hino immediately if low air pressure warning comes on. Allow the compressor to build pressure; if it fails, do not drive — have the air system repaired by a certified Hino technician.

Engine Overheating

Common causes

  • Coolant leak
  • Failed thermostat
  • Clogged radiator or fan failure

What to do

Pull over safely, let the Hino's J08/A09 engine idle briefly, then shut down. After cooling, check coolant level and look for leaks. Do not drive until temperature returns to normal.

DEF System Malfunction

Common causes

  • Low DEF level
  • DEF pump failure
  • Contaminated DEF fluid

What to do

If the DEF light illuminates, refill with fresh AdBlue. If it persists, the Hino's SCR system may need service — continued driving will lead to engine derate. Visit a Hino dealer.

Low Oil Pressure

Common causes

  • Low oil level
  • Oil pump failure
  • Worn engine bearings

What to do

Shut down the Hino immediately to prevent catastrophic engine damage. Check the oil level with the dipstick; if low, add oil. If pressure remains low, tow to a Hino service center.

DPF Clogging

Common causes

  • Frequent short trips
  • Failed regeneration
  • Excessive idling

What to do

If the DPF light is steady, drive at highway speeds to initiate passive regen. If flashing, perform a parked regen per the Hino owner's manual, or visit a dealer for forced regeneration.

Frequently Asked Questions

Why does my Hino truck's check engine light come on and then go off?

It could be a temporary sensor fault, but often indicates a pending emission issue. Have the ECM scanned by a Hino dealer to retrieve stored codes.

What does the 'water in fuel' light mean on my Hino?

It means water has accumulated in the fuel/water separator. Drain the separator immediately to prevent injection pump damage.

How long can I drive with the DEF light on in my Hino?

You can typically drive about 500 miles before engine derate occurs, but it's best to refill at the earliest opportunity to avoid power loss.

My Hino truck's transmission temp light flickers on hills — is that normal?

Flickering indicates thermal stress. Shift to a lower gear to reduce load; if it stays on, stop and let the transmission cool.

Should I stop immediately if the red 'air brake' warning comes on?

Yes, a red air brake warning means pressure is below 60 psi. Stop in a safe place and let the compressor rebuild pressure. Do not drive until the light extinguishes.

Why does the DPF regeneration light stay on even after driving?

The Hino may be in a passive regen state. If it remains on after a long drive, the filter may be clogged; schedule a forced regen at a Hino dealer.