Kenworth T600 Warning Lights and Symbols (Meaning and Fixes)

The Kenworth T600 instrument cluster provides critical vehicle status through a combination of analog gauges and digital warning symbols. Designed for long-haul trucking, it emphasizes engine, braking, and after-treatment system alerts to keep the driver informed and safe.

How to read the colors: Red indicators demand immediate action (stop), amber warns of service needs or caution, while green/blue indicate normal operation or activated features.

Kenworth T600 Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDLights up when a critical fault is detected that requires immediate engine shutdown or transmission park.Safely pull over and turn off engine; consult fault codes.
Check Engine (MIL)AMBERIndicates an emission or powertrain fault that may reduce fuel economy or performance on your T600.Schedule diagnostics at the next stop; monitor other gauges.
Engine Oil PressureREDLow engine oil pressure detected, could be due to low level, pump failure, or a blocked filter.Immediately shut down engine to prevent damage; check oil level.
Battery / ChargingREDAlternator not charging or battery voltage is low, risking electrical system failure.Check belt tension and connections; have alternator tested.
Coolant TemperatureREDEngine coolant is overheating, possibly from low coolant, failed thermostat, or radiator blockage.Stop engine and let cool; check coolant level and fan operation.
Brake SystemREDGeneral brake system fault, like low air pressure or hydraulic leak, on your T600.Stop safely; do not drive until brakes are inspected.
ABSABSAMBERAnti-lock brake system fault; standard brakes still function but ABS is disabled.Service ABS as soon as possible; drive cautiously on slippery roads.
PParking BrakeREDParking brake is engaged or malfunctioning; if engaged while driving, it will apply.Ensure parking brake is fully released; if light stays on, check air system.
Tire Pressure (TPMS)AMBEROne or more tires have low pressure, affecting fuel efficiency and safety.Check and adjust tire pressures at the next rest stop.
Glow Plug / PreheatAMBERGlow plugs are heating (or a fault exists) for cold start on your T600's diesel engine.Wait for light to turn off before starting; if flashing, service glow plugs.
DPF / RegenerationAMBERDiesel particulate filter needs regeneration to prevent clogging; may be in process.If flashing, drive at highway speed to initiate regen; if solid, follow manufacturer procedure.
DEF / AdBlueAMBERDiesel exhaust fluid level is low or quality poor, affecting emissions and engine power.Add DEF at next opportunity; use approved fluid.
Water in FuelAMBERWater detected in fuel/water separator; can cause injector damage.Drain water separator at the fuel filter housing.
Low FuelAMBERFuel level is low; you have limited range to find a station.Refuel as soon as possible to avoid running out.
High BeamBLUEHigh beam headlights are turned on for better nighttime visibility.Dim when approaching oncoming traffic.
Power Steering (EPS)REDElectric or hydraulic power steering failure, making steering heavy.Stop for inspection; do not drive without power steering.
Fasten Seat BeltREDDriver or passenger seat belt is not fastened.Buckle up before moving the truck.
Reduced Power (Limp Mode)AMBEREngine has entered limp mode to protect the drivetrain due to a fault.Service engine soon; limited speed allowed.
AIRAir Brake Pressure (Low)REDAir pressure in brake system is dangerously low, braking ability compromised.Stop immediately; wait for compressor to build pressure or call service.
EBEngine / Exhaust BrakeGREENEngine brake or exhaust brake is activated to assist slowing.Normal operation; disengage when not needed.
TrailerGREENTrailer electrical connection is detected and functional.Confirm trailer is connected properly.
Door OpenREDCab door is open or not fully closed.Close the door securely before driving.
High Exhaust Temp (HEST)AMBERExhaust system temperature is elevated, often during regeneration.Avoid parking on flammable materials; regen completes soon.

23 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
  • Faulty thermostat
  • Radiator blockage
  • Broken fan belt

What to do

Pull over safely with T600, let engine idle a few minutes then shut off; check coolant reservoir and fan operation; do not open hot radiator cap.

Low Oil Pressure

Common causes

  • Low oil level
  • Oil pump failure
  • Clogged oil filter
  • Internal engine wear

What to do

Immediately stop the engine on your T600; check dipstick; add oil if low; if light persists, tow to service.

Air Brake Failure

Common causes

  • Compressor malfunction
  • Air leak in lines
  • Low air pressure
  • Frozen moisture in winter

What to do

Stop as soon as safely possible; allow compressor to build air; inspect for leaks; if unable to build pressure, call roadside assistance for your T600.

DEF System Malfunction

Common causes

  • Empty DEF tank
  • Poor quality DEF
  • DEF injector clogged
  • Heater fault

What to do

Refill with approved DEF; if light remains, a dealer must reset the system; engine power may be reduced until fixed.

DPF Clogged

Common causes

  • Frequent short trips
  • Excessive idling
  • Engine tuning issues
  • Failed regeneration

What to do

Drive at highway speed for 20-30 minutes to initiate regen; if light flashes or stays on, service DPF at Kenworth dealership.

Frequently Asked Questions

Why does my T600's Check Engine light come on during heavy load?

Heavy load strains the engine and emissions system; possible causes include EGR valve issue or DPF pressure high. Have codes read to diagnose.

What does the 'Water in Fuel' light mean and how do I fix it?

Water separator has accumulated water; drain by turning the drain valve at the bottom of the fuel filter housing until clear fuel appears.

Why is my DEF light on even after refilling?

The system may need a reset after refill. Drive for a few miles; if it persists, quality is poor or there is a sensor fault requiring service.

Can I drive with the ABS light on in my T600?

Yes, but without ABS. Standard brakes work. Drive carefully with reduced traction and get ABS sensor/wiring checked soon.

How do I initiate a parked DPF regeneration on a T600?

Park safely, engage parking brake, press and hold the DPF regen switch (if equipped) until the regen process starts; follow dash prompts.

What causes the Air Brake Low Pressure warning on start?

After overnight, air may have leaked. Let compressor run; if pressure doesn't build within 2 minutes, there's a leak or compressor issue.