Kenworth C500 Warning Light Symbols and What They Mean

The Kenworth C500 is a rugged heavy-duty truck designed for demanding off-road and on-highway applications. Its instrument cluster features a comprehensive set of warning lights and gauges to keep the driver informed of vehicle status and potential issues.

How to read the colors: Red lights indicate a critical fault requiring immediate attention; amber lights signal a caution or non-critical system issue; green or blue lights are status indicators for normal operation.

Kenworth C500 Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDA critical system fault has been detected on your C500 that requires immediate vehicle shutdown.Safely pull over, stop the engine, and consult the fault code display.
Master CautionAMBERA non-critical system issue is present on your C500; check the message center for details.Review the dashboard messages and address the related system soon.
Check Engine (MIL)AMBERThe engine control module has detected a malfunction in emissions or performance systems on your C500.Schedule a diagnostic scan at a Kenworth dealer as soon as possible.
Engine Oil PressureREDEngine oil pressure has dropped below safe operating levels for your C500's PACCAR engine.Stop the engine immediately and check oil level; do not restart until resolved.
Battery / ChargingREDThe charging system voltage is too low or too high, indicating alternator or battery issues on your C500.Reduce electrical load and have the charging system inspected.
Coolant TemperatureREDEngine coolant temperature has exceeded the maximum safe limit for your C500.Pull over, idle engine to cool down, and check coolant level.
ATTransmission TempAMBERTransmission fluid temperature is higher than normal in your C500's Eaton Fuller transmission.Reduce load and shift to a lower gear to aid cooling.
Brake SystemREDA fault has been detected in the brake system of your C500, potentially affecting stopping performance.Stop the vehicle safely and have brakes inspected immediately.
ABSABSAMBERThe anti-lock braking system on your C500 has a fault; standard brakes still function but ABS is disabled.Drive cautiously and have the ABS system serviced soon.
PParking BrakeREDThe parking brake is engaged or a fault exists in the parking brake system on your C500.Release the parking brake before driving; if light stays on, check the system.
Tire Pressure (TPMS)AMBEROne or more tires on your C500 have low pressure, affecting handling and fuel economy.Check and inflate tires to recommended pressure at next stop.
Seat BeltREDThe driver or passenger seat belt is not fastened in your C500.Fasten seat belts for all occupants before driving.
High BeamBLUEThe high beam headlights are activated on your C500.Dim when approaching oncoming traffic.
Low FuelAMBERThe fuel level in your C500 is low and you should refuel soon.Refuel at the nearest station to avoid running out.
DPF / RegenerationAMBERThe diesel particulate filter on your C500 needs cleaning through regeneration.Drive at highway speeds to allow passive regeneration or initiate active regeneration.
DEF / AdBlueAMBERThe DEF level in your C500 is low or the DEF system has a fault, possibly limiting engine power.Top up DEF fluid immediately to maintain emissions compliance.
Water in FuelAMBERWater has been detected in the fuel system of your C500, which can cause injector damage.Drain the fuel/water separator as soon as possible.
AIRAir Brake Pressure (Low)REDThe air brake system pressure in your C500 is below the safe operating level.Stop the vehicle and allow the air compressor to build pressure; do not drive until pressure is normal.
EBEngine / Exhaust BrakeGREENThe engine or exhaust brake is engaged on your C500, providing additional slowing force.Use on downgrades to reduce brake wear.
Check Engine (MIL)AMBEREmissions-related fault detected in your C500's PACCAR engine; may affect performance.Have the engine diagnosed at a Kenworth service center.

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

Most Important Warning Lights

Brake System Failure

Common causes

  • Air leak in brake lines
  • Worn brake pads or shoes
  • Low air pressure in reservoir

What to do

For your Kenworth C500, immediately stop the vehicle when safe. Check air brake system for leaks and have the brakes inspected by a qualified technician before resuming operation.

Engine Overheating

Common causes

  • Low coolant level
  • Failed cooling fan or thermostat
  • Radiator blockage

What to do

On your C500, pull over and idle the engine to circulate coolant. After cooling, top up coolant and check for leaks. If recurring, visit a Kenworth dealer for cooling system service.

Low Oil Pressure

Common causes

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

What to do

Shut down the C500 engine immediately. Check oil level and add if needed. If the light remains on, do not restart; have the oil system inspected by a mechanic.

Charging System Fault

Common causes

  • Faulty alternator
  • Bad battery connection
  • Worn drive belt

What to do

In your C500, reduce electrical load (lights, AC) and drive to a service area. Have the alternator and battery tested; replace components as needed.

Frequently Asked Questions

What does the master warning light mean on my Kenworth C500?

The red master warning light indicates a critical fault that requires immediate action. Stop the vehicle safely, turn off the engine, and consult the display for specific fault codes.

How do I initiate DPF regeneration on my C500?

Your C500 can perform passive regeneration during highway driving. If the amber DPF light appears, drive at speeds above 30 mph for 20–30 minutes to clear the filter. Alternatively, use the dash-mounted regen switch if equipped.

Why is the amber tire pressure light on?

The TPMS on your C500 detects low pressure in one or more tires. Check all tires with a gauge and inflate to the pressure listed on the driver's door jamb (typically 100-120 psi for steer tires).

What should I do if the air brake pressure warning comes on?

The red air brake light indicates low pressure in the system. Stop the truck immediately and let the engine run to allow the compressor to build pressure (typically above 100 psi). Do not move until the light goes off.

Can I continue driving with the check engine light on?

If the amber check engine light is steady, you may continue driving to a service center, but avoid heavy loads. If it flashes, reduce power and stop as soon as possible to prevent catalyst damage.

How often should I service my C500's DEF system?

The DEF system requires periodic refills of Diesel Exhaust Fluid. Top up when the amber DEF light appears, typically every 5,000–10,000 miles depending on usage. Use only API-certified DEF.