New Holland T5.120 Warning Lights and Symbols (Meaning and Fixes)

Quick answer: These dashboard warning lights follow the ISO 2575 international standard. A red symbol means stop the machine and check immediately, amber or yellow means service soon, and green or blue symbols are normal status indicators. Each symbol below is explained with its meaning, the most likely cause, and the recommended action.

The New Holland T5.120 is a versatile utility tractor equipped with a 4.5L engine and a comprehensive digital instrument cluster. Warning lights include engine, transmission, hydraulic, and emissions systems to ensure safe operation and maintenance alerts.

How to read the colors: Red indicates an immediate stop and check required; amber warns of a condition needing attention; green or blue shows a system is active or operating normally.

New Holland T5.120 Warning Light Symbols

SymbolNameColorWhat it meansWhat to do
Master Warning (Stop)REDIlluminates together with another red warning to indicate a critical fault that requires immediate engine shutdown on the T5.120.Stop the engine safely and consult the fault code displayed in the digital cluster.
Master CautionAMBERLights up with an amber warning to alert the operator of a non-critical condition needing attention on your T5.120.Check the instrument panel for accompanying symbols and address the related system.
Check EngineAMBERIndicates an engine management issue, such as a sensor fault or emission system problem, specific to the T5.120's 4.5L engine.Have the engine diagnosed by a New Holland dealer as soon as possible.
Engine Oil PressureREDWarns that engine oil pressure is below safe levels, which could cause severe damage to the T5.120's engine.Immediately stop the engine and check the oil level and pressure sensor.
Battery / ChargingREDIndicates the battery is not charging properly or the charging system has failed on the T5.120.Check alternator belt tension and battery connections; if persistent, seek service.
Coolant TemperatureREDEngine coolant temperature has exceeded the safe operating range for your T5.120.Reduce engine load immediately and allow the engine to cool; check coolant level and fan operation.
ATTransmission TempREDTransmission oil temperature is too high, risking damage to the T5.120's gearbox.Shift to neutral, reduce engine speed, and allow transmission to cool; check oil level.
Brake SystemREDIndicates a fault in the brake system, such as low brake fluid or a worn lining on the T5.120.Stop the tractor safely and inspect brake fluid level and lines.
PParking BrakeAMBERReminds the operator that the parking brake is engaged on the T5.120.Release the parking brake before moving the tractor.
Glow Plug / PreheatAMBERIndicates the preheat cycle is active for cold starting the T5.120's diesel engine.Wait for the light to turn off before cranking the engine.
DPF / RegenerationAMBERThe diesel particulate filter needs regeneration to clear accumulated soot in the T5.120's exhaust system.Drive the tractor at higher engine loads or initiate parked regeneration if stationary.
DEF / AdBlueAMBERAdBlue level is low or quality is poor, affecting emissions compliance on the T5.120.Refill with fresh AdBlue diesel exhaust fluid.
Water in FuelAMBERWater has been detected in the fuel separator, which can damage the T5.120's injection system.Drain the water from the fuel filter separator as soon as possible.
Low FuelAMBERFuel level is critically low and the T5.120 may soon run out of diesel.Refuel immediately to avoid air entering the fuel system.
High BeamBLUEThe high beam headlights are activated for improved visibility on the T5.120.Dim to low beam when approaching other vehicles.
Power Steering (EPS)AMBERIndicates reduced power steering assist due to low fluid or a fault in the T5.120's system.Check hydraulic oil level and inspect for leaks; if light stays, seek service.
Hydraulic SystemAMBERA general hydraulic system warning, such as low oil level or filter restriction on the T5.120.Check hydraulic oil reservoir and filters; reduce load if necessary.
Air FilterAMBERThe engine air intake filter is clogged and needs replacement for the T5.120.Replace the air filter element to prevent engine power loss.
Fuel Filter / Water SeparatorAMBERThe fuel filter is restricted or water separator needs draining on the T5.120.Replace the fuel filter and drain any water from the separator.
Service / Hour MeterAMBERIndicates a scheduled maintenance interval has been reached for the T5.120.Perform the required service as listed in the operator's manual.
Work LightsGREENThe rear or front work lights are turned on for field operations on the T5.120.Turn off work lights when driving on public roads.
Beacon / Rotating LightGREENThe amber rotating beacon is active to indicate the T5.120 is operating in the field.Turn off beacon when not needed to conserve battery.
Differential LockGREENThe rear differential is locked for maximum traction on the T5.120.Disengage differential lock before turning on hard surfaces.
PTOPTO EngagedGREENThe power take-off shaft is engaged and rotating on the T5.120.Disengage PTO before leaving the operator seat.
MINLow Oil LevelAMBEREngine oil level is below the minimum mark, separate from oil pressure warning on the T5.120.Check and add engine oil to the correct level.
Brake Fluid LevelREDBrake fluid level is low, which can reduce braking efficiency on the T5.120.Stop safely and top up brake fluid with recommended type.

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

Most Important Warning Lights

DPF Regeneration Required

Common causes

  • Short low-load operation cycles
  • Excessive idling
  • Fuel or oil quality issues

What to do

On the T5.120, drive at higher engine loads (above 1500 rpm) for 15-20 minutes to initiate passive regen, or use the parked regen function via the instrument cluster menu.

Low AdBlue Level

Common causes

  • Not refilling AdBlue after warning
  • Leaks in the AdBlue tank or lines
  • Using contaminated fluid

What to do

Refill with genuine New Holland AdBlue at the fill cap located on the left side of the T5.120; the system will automatically reset after a short drive.

Transmission Overheating

Common causes

  • Continuous heavy load in high gear
  • Low transmission oil level
  • Clogged cooler fins

What to do

For the T5.120, reduce load, shift to a lower gear, and idle to cool; check transmission oil level and clean the cooler with compressed air.

Low Engine Oil Pressure

Common causes

  • Low oil level
  • Worn oil pump
  • Clogged oil filter

What to do

Immediately stop the T5.120 engine, check oil level with dipstick, and top up if needed; if light persists, do not restart and contact service.

Water in Fuel Detected

Common causes

  • Condensation in fuel tank
  • Contaminated fuel supply
  • Failed fuel cap seal

What to do

Drain water from the fuel filter water separator (located under the hood on the T5.120) by opening the drain valve until clean fuel flows out.

Frequently Asked Questions

Why does the check engine light flash on my T5.120?

A flashing check engine light indicates a severe misfire or catalyst damage risk; reduce load immediately and have the tractor diagnosed by a dealer.

How do I perform a parked regeneration on the T5.120?

With the engine at operating temperature and the tractor parked in a safe area, press the regen button on the dashboard (or use the menu) and follow the cluster prompts.

What does the transmission temperature light mean when towing?

It means the transmission oil is too hot; shift to a lower range, reduce ground speed, or stop and idle to cool the transmission.

How often should I change the hydraulic oil on the T5.120?

New Holland recommends every 600 hours or annually, but check the service hour meter light and manual for specific intervals based on usage.

Can I clear the water-in-fuel warning myself?

Yes, drain the water separator on the T5.120 (turn the drain knob counterclockwise) until clean fuel flows, then tighten; the light will reset after a few seconds.

Why does the master caution light stay on after starting?

It usually means one or more amber warnings are active; scroll through the cluster display to identify which system needs attention.