International LoneStar Warning Lights and Symbols (Meaning and Fixes)

The International LoneStar's instrument cluster combines classic styling with modern digital displays, featuring a distinctive chrome-trimmed gauge cluster that emphasizes both aesthetics and functionality. Key warnings are centered around the driver's primary field of view, with bright LED indicators for critical alerts.

How to read the colors: Red indicators demand immediate attention and signify a critical failure, amber indicates a cautionary condition that requires service soon, while green or blue lights confirm system activation or normal operation.

International LoneStar Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDIlluminates as a red stop sign symbol to indicate a serious fault that requires immediate engine shutdown or vehicle stop on your LoneStar.Safely pull over and turn off the engine; consult the message center for the specific fault.
Master CautionAMBERThis amber caution light appears as an exclamation mark inside a triangle, alerting you that a secondary system needs attention soon on your LoneStar.Check the driver information display for the related warning and schedule service promptly.
Check Engine (MIL)AMBERWhen this engine silhouette symbol glows amber, it indicates a malfunction in the emissions or engine control system specific to your LoneStar's International N13 or Cummins ISX.Reduce speed and have the engine diagnostics checked at the next service stop.
Engine Oil PressureREDThis old-fashioned oil can symbol turns red when oil pressure drops below safe levels, risking severe engine damage in your LoneStar.Immediately shut off the engine and check oil level; do not restart until resolved.
Battery / ChargingREDA red battery icon indicates the charging system voltage is too low or the alternator has failed on your LoneStar.Check alternator belt and connections; if light persists, have the charging system tested.
Coolant TemperatureREDWhen the thermometer symbol glows red, your LoneStar's coolant temperature has exceeded the normal range, risking overheating.Pull over, let engine idle to cool, then check coolant level and fan operation.
Brake SystemREDA red circle with 'BRAKE' text illuminates for low brake fluid or a system fault in your LoneStar's air-over-hydraulic or full air brakes.Stop safely, check brake fluid reservoir or air pressure; do not drive until corrected.
ABSABSAMBERAn amber 'ABS' indicator signifies a fault in the antilock braking system on your LoneStar, but normal braking remains functional.Have the ABS system diagnosed at a service center; drive cautiously on slippery roads.
PParking BrakeREDThe red 'P' with a circle indicates the parking brake is engaged on your LoneStar; it may be combined with a brake air pressure warning.Release the parking brake before moving; if light stays on, check air pressure or brake valve.
Tire Pressure (TPMS)AMBERAn amber horseshoe with an exclamation point alerts you that one or more tires on your LoneStar have low pressure.Check tire pressures at next stop and inflate to recommended levels.
Seat BeltREDA red driver silhouette with a lap belt icon reminds you that the driver's seat belt is unbuckled in your LoneStar.Buckle the seat belt immediately while the vehicle is in motion.
Glow Plug / PreheatAMBERThis amber coil symbol illuminates during cold starts to indicate the intake air heater or glow plugs are active on your LoneStar's diesel engine.Wait for the light to turn off before cranking the engine in cold weather.
DPF / RegenerationAMBERA soot filter icon glows amber when the diesel particulate filter needs active regeneration on your LoneStar to clear accumulated soot.Drive at highway speeds to enable automatic regeneration, or perform a parked regen per instructions.
DEF / AdBlueAMBERAn amber tank with drops indicates low Diesel Exhaust Fluid level in your LoneStar, affecting emissions compliance.Refill DEF at next stop; if ignored, vehicle speed may be limited.
Water in FuelAMBERA fuel pump with a water drop icon alerts you that water has accumulated in the fuel/water separator on your LoneStar.Drain the water separator immediately to prevent fuel system damage.
Low FuelAMBERA fuel pump symbol illuminates amber when your LoneStar's fuel level is low, requiring refueling soon.Refuel at the nearest station to avoid running out of diesel.
High BeamBLUEA blue headlight symbol confirms the high beam headlights are activated on your LoneStar, providing extended road illumination.Switch to low beams when approaching oncoming traffic to avoid glare.
Reduced Power (Limp Mode)AMBERA turtle icon or engine with a downward arrow indicates your LoneStar has entered reduced power mode to protect the drivetrain.Drive to a safe location and have the engine and transmission codes read.
Air FilterAMBERAn engine air intake symbol warns that the air filter is restricted on your LoneStar, reducing performance.Inspect and replace the air filter as soon as possible.
Fuel Filter / Water SeparatorAMBERA fuel filter icon indicates clogged fuel filter or water in the separator on your LoneStar; may appear together with water in fuel light.Replace the fuel filter and drain water separator.
Service / Hour MeterAMBERA wrench icon or clock symbol reminds you that scheduled maintenance is due based on engine hours on your LoneStar.Consult the service schedule and perform required maintenance.
Work LightsGREENA light bulb symbol with beams indicates the auxiliary work lights are turned on for nighttime jobs on your LoneStar.Turn off work lights when not needed to conserve battery and avoid blinding others.
Beacon / Rotating LightGREENA flashing beacon icon confirms the roof-mounted warning light is active on your LoneStar for visibility at job sites.Activate beacon only when vehicle is stationary or in low-speed work zones.
Differential LockAMBERA differential gear symbol with a lock indicates the inter-axle or cross-axle differential lock is engaged on your LoneStar for traction.Disengage differential lock when on dry pavement to prevent driveline damage.
PTOPTO EngagedGREENA gear with a power take-off icon shows the PTO is engaged on your LoneStar for auxiliary equipment operation.Ensure transmission is in neutral before engaging PTO; disengage when not in use.
AIRAir Brake Pressure (Low)REDA red circle with 'AIR' or a brake gauge symbol indicates low air pressure in your LoneStar's air brake system, a critical safety condition.Stop the vehicle immediately and wait for air pressure to build; do not drive until pressure is normal.
EBEngine / Exhaust BrakeGREENA brake with waves symbol confirms the engine or exhaust brake is activated on your LoneStar to assist downhill braking.Use on downgrades to reduce service brake wear; deactivate on slippery roads if wheel slip occurs.
TrailerGREENA trailer icon illuminates green when a trailer is properly connected and the electrical system is active on your LoneStar.Verify trailer lights and brakes before departure; if light stays off, check trailer connection.
Door OpenREDA red truck silhouette with an open door alerts you that a door is ajar on your LoneStar.Close all doors securely before driving.
High Exhaust Temp (HEST)AMBERAn amber exhaust pipe with heat waves warns that the exhaust temperature is high during DPF regeneration on your LoneStar.Avoid parking near flammable materials; regeneration will complete automatically.
Washer Fluid LowAMBERA windshield with spray icon indicates the washer fluid reservoir is low on your LoneStar, affecting visibility cleaning.Refill washer fluid with a winter-grade solution if in freezing temperatures.

31 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 fan failure
  • Clogged coolant passages

What to do

On your LoneStar, immediately reduce engine load and idle; if temperature doesn't drop, shut off engine and allow to cool before checking coolant reservoir and fan operation.

Low Oil Pressure

Common causes

  • Low engine oil level
  • Oil pump failure
  • Diluted or degraded oil

What to do

Stop the LoneStar engine immediately; check oil level with dipstick; if low, add recommended oil. If light remains, do not operate and call for service.

Brake System Failure

Common causes

  • Air brake system leak
  • Low brake fluid (hydraulic)
  • Worn brake pads

What to do

On your LoneStar with air brakes, check air pressure gauge; if below 60 psi, do not drive. For hydraulic brakes, inspect fluid reservoir and top off; if light stays, have brakes inspected.

Charging System Failure

Common causes

  • Broken alternator belt
  • Faulty alternator
  • Battery cable corrosion

What to do

Check alternator belt tension and battery connections on your LoneStar; if belt is loose or missing, replace. If light persists, alternator may need replacement.

DEF System Malfunction

Common causes

  • Empty DEF tank
  • Faulty DEF injector
  • Contaminated DEF fluid

What to do

Refill DEF tank with approved fluid; if indicator remains, you may experience reduced speed. Visit an International dealer for system diagnosis.

Frequently Asked Questions

What does the red stop sign symbol mean on my LoneStar?

That is the Master Warning (Stop) indicator; it signals a critical fault requiring immediate engine shutdown. Pull over safely and consult the message center for the specific issue.

Why is my amber check engine light on and how do I reset it?

The Check Engine light indicates an emissions or engine control fault. On your LoneStar, it cannot be reset by disconnecting the battery; you must have the diagnostic trouble codes read and fixed by a technician.

How do I perform a parked regeneration (regen) on my LoneStar?

Ensure the truck is parked on a non-flammable surface, elevate engine speed to ~1500 RPM, and press the regen switch on the dash (if equipped). The process takes about 20 minutes; do not leave unattended.

What does the amber coil light mean and how long should I wait?

That's the glow plug/preheat light for cold starts. On your LoneStar, wait until it turns off before cranking; typically 5-15 seconds depending on engine temperature.

My low air pressure warning is on; can I still drive?

No. The red 'AIR' light indicates your LoneStar's air brake pressure is below 60 psi. Do not move the vehicle; allow the air compressor to build pressure to at least 100 psi before releasing the parking brake.

How often should I drain the water separator on my LoneStar?

Drain the fuel/water separator monthly or when the water-in-fuel light appears. Also, replace the fuel filter every 15,000-20,000 miles or per your maintenance schedule.