The New Holland T4.90 tractor features a comprehensive instrument cluster with warning lights and indicators to keep you informed of machine health and status. Understanding these symbols helps ensure safe operation and timely maintenance on your T4.90.
New Holland T4.90 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | This red stop light illuminates on your T4.90 instrument panel when a critical fault has been detected that requires immediate stopping of the engine. | Stop the tractor safely, shut off the engine, and consult the operator's manual or contact your dealer. | |
| Master Caution | AMBER | An amber caution light on your T4.90 alerts you to a non-critical system issue that should be checked soon to prevent escalation. | Review the additional warning lights and check the info display for messages. | |
| Check Engine (MIL) | AMBER | This light indicates an emission-related problem with your T4.90's engine management system, possibly affecting performance or compliance. | Service the engine at your earliest convenience; if flashing, reduce load and contact a dealer. | |
| Engine Oil Pressure | RED | When lit red, your T4.90's engine oil pressure is dangerously low, risking severe engine damage. | Stop the engine immediately and check oil level; do not restart until resolved. | |
| Battery / Charging | RED | This red light on your T4.90 indicates the battery is not being charged properly, often due to alternator or wiring fault. | Check battery connections and alternator belt; charge or replace battery as needed. | |
| Coolant Temperature | RED | A red coolant temperature light warns that the engine coolant in your T4.90 has exceeded safe operating temperature. | Reduce engine load and idle to cool; check coolant level and radiator for debris. | |
| Transmission Temp | AMBER | The amber transmission temperature light indicates the hydraulic/transmission oil in your T4.90 is too hot, potentially reducing component life. | Shift to a lower gear or reduce load; allow transmission to cool. | |
| Brake System | RED | This red warning indicates a problem with your T4.90's service brakes, such as low fluid or worn pads. | Check brake fluid level and inspect for leaks; do not operate until brakes are functional. | |
| Parking Brake | AMBER | An amber parking brake light reminds you that the parking brake is engaged on your T4.90. | Release the parking brake before moving. | |
| Glow Plug / Preheat | AMBER | This amber indicator shows the glow plugs are active during cold start preheating of your T4.90 diesel engine. | Wait for the light to turn off before cranking the engine. | |
| DPF / Regeneration | AMBER | The amber DPF light signals that the diesel particulate filter on your T4.90 is regenerating to burn off soot. | Continue normal operation to complete regeneration; do not idle for extended periods. | |
| DEF / AdBlue | AMBER | This amber indicator warns that the DEF level in your T4.90 is low or there is a system fault with the SCR system. | Refill DEF at the next opportunity; if light persists, consult a dealer. | |
| Water in Fuel | AMBER | When lit, water has been detected in the fuel filter/water separator of your T4.90, which can cause injection damage. | Drain fuel filter/separator immediately according to the operator's manual. | |
| Low Fuel | AMBER | This amber light indicates the fuel tank level on your T4.90 is low and needs refilling soon. | Refuel as soon as possible to avoid running out. | |
| High Beam | BLUE | A blue high-beam indicator confirms that the headlights are set to high beam on your T4.90. | Dim when approaching other vehicles. | |
| Hydraulic System | AMBER | This amber light signals an issue with the hydraulic system of your T4.90, such as low fluid or filter restriction. | Check hydraulic oil level and condition; inspect for leaks. | |
| PTO Engaged | AMBER | An amber light shows that the power take-off on your T4.90 is engaged and rotating. | Disengage PTO before performing maintenance or when not needed. | |
| Differential Lock | AMBER | This amber indicator illuminates when the differential lock on your T4.90 is engaged for increased traction. | Disengage diff lock when turning or on hard surfaces. | |
| Air Filter | AMBER | The amber air filter light indicates a restriction in the engine air intake filter on your T4.90. | Clean or replace the air filter element as per maintenance schedule. |
19 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Engine Coolant Overheat
Common causes
- Low coolant level
- Faulty thermostat
- Clogged radiator
What to do
On your New Holland T4.90, stop the engine immediately, let it cool, then check coolant level and refill if low. Clean radiator fins of debris. If the issue persists, inspect the thermostat and water pump.
Low Engine Oil Pressure
Common causes
- Low oil level
- Oil pump failure
- Clogged oil filter
What to do
Stop the engine on your T4.90 right away. Check the dipstick and add oil if low. If oil level is correct, the oil filter may be clogged or the oil pump may be failing – contact your dealer for service.
DEF/AdBlue System Malfunction
Common causes
- Empty DEF tank
- Contaminated DEF fluid
- Faulty injector or sensor
What to do
On the T4.90, refill with fresh DEF using a clean funnel. If the warning remains, the system may have a clogged injector or a sensor fault; schedule diagnostic service with your New Holland dealer.
DPF Regeneration Required
Common causes
- Excessive idling
- Low exhaust temperature
- Clogged DPF
What to do
To allow regeneration on your T4.90, operate the tractor under moderate load for 20-30 minutes. If the light stays on, a forced regeneration may be needed at the dealer.
Transmission Overheating
Common causes
- Overloading
- Low transmission oil level
- Restricted oil cooler
What to do
Reduce the load on your T4.90 and shift to a lower gear. Check the transmission oil level and add if necessary. Clean the oil cooler fins and ensure proper airflow.
Frequently Asked Questions
What should I do if the red Master Warning light comes on while operating my T4.90?
Stop the tractor immediately, turn off the engine, and check the info display for additional warnings. Do not restart until the underlying issue is resolved, such as low oil pressure or overheating.
Why does the amber DPF light stay on for a long time during regeneration?
On the T4.90, prolonged DPF regeneration may indicate that the exhaust temperature is too low to burn off soot. Try operating at higher engine speeds and loads to facilitate regeneration.
Can I drive my T4.90 with the amber Check Engine light on?
Yes, but you should have it serviced soon. The amber light indicates an emission-related issue that may affect performance and fuel economy. Avoid heavy loads until checked.
How often should I drain the water separator on my T4.90?
Check it daily, especially in humid conditions or after refueling. Drain whenever the Water in Fuel light comes on or during routine maintenance every 100 hours.
What does the blue High Beam indicator mean for night work?
It simply shows that the high beams are on. Lower them when approaching other vehicles or when working near buildings to avoid blinding others.
Is it normal for the glow plug light to flash on a cold start?
On the T4.90, a steady amber glow plug light indicates preheating; usually it stays on for a few seconds and then turns off. Flashing could indicate a fault in the glow plug system – consult your dealer.