Volvo Trucks VNL Warning Lights and Symbols (Meaning and Fixes)

The Volvo VNL's instrument cluster uses a color-coded warning system to alert drivers of vehicle status and faults. Red lights indicate critical issues requiring immediate attention, while amber lights signal cautionary conditions. Blue and green lights are informational, such as high beam or trailer connection.

How to read the colors: Red lights mean stop immediately and address the issue. Amber lights advise caution and prompt action soon; green or blue lights are status indicators only.

Volvo Trucks VNL Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDA critical system fault detected on your Volvo VNL requires immediate stop and evaluation.Safely pull over, shut down engine, and consult the Volvo VNL driver manual or contact support.
Master CautionAMBERA non-critical fault exists in one of the Volvo VNL systems; investigate soon.Check the display for specific warnings and schedule service at your nearest Volvo dealer.
Check Engine (MIL)AMBERAn emissions-related fault has been detected in the Volvo D13 or D11 engine control system.Use Volvo's diagnostic tools to read codes; avoid prolonged driving to prevent increased emissions.
Engine Oil PressureREDEngine oil pressure is critically low in your Volvo VNL; continued operation can cause severe damage.Stop engine immediately, check oil level, and inspect for leaks before restarting.
Battery / ChargingREDThe Volvo VNL's charging system or battery voltage is outside normal range.Check alternator belt tension and battery connections; if light persists, have charging system tested.
Coolant TemperatureREDEngine coolant temperature has exceeded safe limits for your Volvo VNL's D13 engine.Pull over, let engine idle to cool, and check coolant level and fan operation.
ATTransmission TempAMBERTransmission fluid temperature is elevated in your Volvo I-Shift; heavy load or low fluid may cause this.Reduce load, shift to a lower gear, and allow transmission to cool; check fluid level when stopped.
Brake SystemREDA fault in the Volvo VNL's brake system, such as low air pressure or brake wear, requires immediate attention.Stop vehicle safely, check brake air pressure, and inspect brake components before proceeding.
ABSABSAMBERThe Anti-lock Braking System on your Volvo VNL has detected a fault; standard braking remains active.Drive with caution and have the ABS system diagnosed at a Volvo service center.
PParking BrakeREDThe parking brake is engaged on your Volvo VNL; ensure it is released before driving.Release the yellow knob; if light stays on, check parking brake valve adjustment.
Tire Pressure (TPMS)AMBEROne or more tires on your Volvo VNL are significantly underinflated.Check tire pressures at the nearest safe location and inflate to the recommended PSI listed on the door placard.
Airbag (SRS)REDThe Supplemental Restraint System in your Volvo VNL has a fault; airbags may not deploy in a crash.Have the SRS system inspected by a Volvo technician immediately; do not ignore this light.
Fasten Seat BeltREDThe driver or passenger seat belt in your Volvo VNL is not fastened.Buckle the seat belt; for passenger seats, check that all occupants are belted.
Glow Plug / PreheatAMBERThe glow plugs are preheating the Volvo D13 engine for cold starts; wait until light turns off.Turn ignition to run position and wait for the light to go out before cranking the engine.
DPF / RegenerationAMBERThe Diesel Particulate Filter in your Volvo VNL is actively regenerating to burn off soot.Maintain highway speed to complete regeneration; if light flashes, pull over to enable stationary regen.
DEF / AdBlueAMBERDiesel Exhaust Fluid level is low in your Volvo VNL; engine power may be reduced if depleted.Refill DEF tank at a pump or with a jug; use only API-certified DEF fluid compatible with Volvo SCR systems.
Water in FuelAMBERWater has been detected in the fuel system of your Volvo VNL; drain the water separator soon.Drain the fuel/water separator located on the driver-side frame rail using the valve at the bottom.
Low FuelAMBERFuel level in your Volvo VNL's tank is critically low; you have approximately 50 miles of range remaining.Refuel at the nearest diesel station; do not run the tank dry to avoid priming the fuel system.
High BeamBLUEThe high beam headlights are activated on your Volvo VNL.Dim your high beams when approaching oncoming traffic to avoid blinding other drivers.
Power Steering (EPS)AMBERThe electric power steering system in your Volvo VNL has a fault; steering effort may increase.Check power steering fluid level (if hydraulic) or have EPS system diagnosed; drive cautiously.
AIRAir Brake Pressure (Low)REDAir brake system pressure in your Volvo VNL is below the safe operating threshold.Do not drive; build air pressure by revving engine or connecting to shop air; check for air leaks.
TrailerGREENA trailer is electrically connected and recognized by your Volvo VNL's system.Verify trailer lights and brakes function; this is a status indicator only.
High Exhaust Temp (HEST)AMBERExhaust temperature is elevated during DPF regeneration on your Volvo VNL; avoid parking over flammable materials.Continue driving; if parking is necessary, avoid dry grass or debris under the exhaust outlet.
Door OpenREDOne of the cab doors on your Volvo VNL is not fully closed.Check all cab doors and ensure they are securely latched before driving.
Washer Fluid LowAMBERWindshield washer fluid level is low in your Volvo VNL.Refill the washer fluid reservoir located under the hood on the passenger side.
Brake Fluid LevelREDBrake fluid level in your Volvo VNL's hydraulic brake system is critically low.Do not drive; check for leaks and top up brake fluid with DOT 4 fluid; have system inspected.

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

Most Important Warning Lights

Check Engine Light On

Common causes

  • Failed emissions component (EGR, DEF injector)
  • Loose or faulty fuel cap
  • Sensor malfunction (NOx, temperature)

What to do

Use Volvo Premium Tech Tool (PTT) to read fault codes. For the Volvo VNL with D13, resetting the light often requires clearing codes after repair.

Low Air Brake Pressure

Common causes

  • Air leak in brake lines or chambers
  • Faulty air compressor governor
  • Moisture freezing in air system (winter)

What to do

Build air pressure with engine at fast idle. Listen for leaks around brake chambers and gladhands. On VNL, the air dryer should be serviced every 2 years.

DEF System Malfunction

Common causes

  • Low DEF quality or level
  • DEF heater failure in cold weather
  • SCR catalyst blockage or sensor error

What to do

Refill with approved DEF fluid. If light persists, drive at highway speed for 30 minutes to regenerate the SCR. For hardened faults, visit a Volvo dealer for software update.

DPF Regeneration Not Completing

Common causes

  • Frequent short trips preventing passive regen
  • Exhaust leak before DPF
  • Soot loading too high for automatic regen

What to do

Initiate stationary regeneration via the switch on the dashboard (press and hold for 5 seconds). Ensure engine is hot and parked safely away from combustibles.

Transmission Overheating

Common causes

  • Overloaded trailer (exceeding GCWR)
  • Prolonged stop-and-go in high ambient temperature
  • Low transmission fluid level or age

What to do

Stop and let the I-Shift cool at idle. Check fluid level using the dipstick on the passenger side of the transmission. If frequently occurring, reduce gross weight or schedule fluid change.

Frequently Asked Questions

What does the amber Master Caution light mean on my Volvo VNL?

It indicates a non-critical system fault, such as low washer fluid or a minor sensor issue. Check the driver information display for the specific warning and address it at your next stop.

Can I drive with the Check Engine light on in my VNL?

Yes, if the light is steady amber, you can continue driving but should have it diagnosed soon. If it flashes, reduce load and seek repair to prevent catalyst damage.

How do I reset the DPF regeneration light on my Volvo VNL?

The light turns off automatically after regeneration completes. To force a stationary regen, press and hold the DPF regen switch on the lower dashboard until the light starts flashing, then follow prompts on the display.

Why does my ABS light stay on after starting the truck?

A fault in the wheel speed sensor or ABS module is present. On the VNL, common causes are corroded sensor connectors at the hubs. A diagnostic scan with Volvo PTT is needed to identify the exact wheel.

What should I do if the Air Brake Pressure light comes on while driving?

Safely pull over immediately. The VNL requires minimum 100 psi to operate brakes. If pressure drops below 60 psi, the emergency brakes will automatically apply. Check for compressor or leak issues.

How often should I service the DEF system on my Volvo VNL?

The DEF filter and level sensor should be inspected every 100,000 miles or annually. Refill the DEF tank every 5,000-10,000 miles depending on usage, using only API-certified DEF fluid.