The New Holland T5.90 tractor features a comprehensive instrument cluster designed to keep you informed of vital system statuses. Its intuitive layout includes a tachometer, fuel gauge, and numerous warning indicators for safe and efficient operation. Understanding these lights is key to maximizing uptime in the field.
New Holland T5.90 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | This red STOP icon appears alongside another warning light to indicate a critical fault that must be resolved before continuing operation. | Stop the engine immediately and consult the display for the associated warning. | |
| Master Caution | AMBER | The amber caution illuminates with other amber lights to draw attention to a non-critical issue that should be addressed soon. | Check the instrument panel display for the specific caution message. | |
| Check Engine (MIL) | AMBER | Indicates a potential engine or emissions system fault; on the T5.90, this often relates to the Tier 4 final engine management. | Have the engine diagnostic codes read by a dealer as soon as possible. | |
| Engine Oil Pressure | RED | Engine oil pressure is critically low, potentially due to low oil level or a failed pump in the T5.90's engine. | Stop the engine immediately and check the oil level. | |
| Battery / Charging | RED | The charging system is not working properly, often from a loose belt or faulty alternator on the T5.90. | Check alternator belt tension and battery connections. | |
| Coolant Temperature | RED | Engine coolant temperature is too high, possibly due to low coolant or a blocked radiator core on the T5.90. | Stop the engine and allow it to cool; check coolant level and radiator cleanliness. | |
| Transmission Temp | AMBER | The transmission fluid temperature is above normal, which can occur during heavy PTO work or high ambient heat. | Reduce load or shift to a lower gear to allow cooling. | |
| Brake System | RED | A fault in the service brake system, such as low brake fluid or worn pads on the T5.90. | Check brake fluid reservoir and inspect for leaks. | |
| Parking Brake | RED | The parking brake is engaged; this light stays on until fully released on the T5.90. | Release the parking brake before moving. | |
| Glow Plug / Preheat | AMBER | The glow plugs are heating the engine for cold starts; light may flash during preheat on the T5.90. | Wait for the light to turn off before starting the engine. | |
| DPF / Regeneration | AMBER | The diesel particulate filter is performing automatic regeneration to clean out soot; may flash if regeneration is active. | Continue normal operation; avoid interrupting the process if possible. | |
| DEF / AdBlue | AMBER | The DEF level is low or there is a system fault; the T5.90 requires DEF to reduce emissions. | Refill with DEF immediately; if light stays on, service required. | |
| Water in Fuel | AMBER | Water has been detected in the fuel filter/water separator; common if fuel quality is poor on the T5.90. | Drain the water separator bowl and replace the fuel filter. | |
| Low Fuel | AMBER | The fuel level is low and you should refuel soon to avoid running out in the field. | Refill the fuel tank. | |
| High Beam | BLUE | High-beam headlights are on; use only when there is no oncoming traffic. | Dim high beams when approaching other vehicles. | |
| Hydraulic System | AMBER | A hydraulic system issue, such as low oil level or a clogged filter on the T5.90. | Check hydraulic oil level and filter condition. | |
| PTO Engaged | GREEN | The power take-off (PTO) is engaged and rotating; ensure safe operation. | Disengage PTO before servicing attachments. | |
| Differential Lock | GREEN | The differential lock is engaged for improved traction on slippery ground. | Disengage when turning on hard surfaces. | |
| Air Filter | AMBER | The engine air filter is restricted and needs cleaning or replacement on the T5.90. | Clean or replace the air filter element. | |
| Fuel Filter / Water Separator | AMBER | The fuel filter is clogged or requires replacement; may also indicate water in the separator. | Replace the fuel filter and drain the water separator. | |
| Work Lights | GREEN | The work lights (rear or front) are activated for nighttime operations. | Turn off when not needed to save battery. | |
| Service / Hour Meter | AMBER | A scheduled service interval has been reached; the T5.90 prompts you based on engine hours. | Perform the required maintenance as per the owner's manual. | |
| Engine Oil Temperature | AMBER | Engine oil temperature is higher than normal; could indicate overloading or low oil level. | Reduce engine load and check oil level. |
23 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Engine Oil Pressure Warning
Common causes
- Low engine oil level
- Oil pump failure
- Clogged oil filter
What to do
On the T5.90, if the oil pressure warning appears, stop the engine immediately. Check the oil level with the dipstick and top up if low. If the light remains after refilling, have the oil pump and filter inspected by a New Holland dealer.
Coolant Overheating
Common causes
- Low coolant level
- Radiator fins blocked with debris
- Faulty thermostat or water pump
What to do
For the T5.90, pull over and let the engine idle (not stop) to cool. Check the coolant reservoir when safe; do not open hot radiator. Clean the radiator core with compressed air. If overheating persists, service the cooling system.
Transmission Overheating
Common causes
- Excessive load or high ambient temperature
- Low transmission fluid
- Clogged transmission cooler
What to do
Reduce ground speed or PTO load to allow the transmission to cool. Check the transmission fluid level on the T5.90 (dipstick near the cab). If low, add specified fluid. Clean the cooler fins if blocked.
Brake System Failure
Common causes
- Low brake fluid
- Brake pad wear
- Leak in brake line
What to do
Immediately stop the tractor safely. Check brake fluid level in the reservoir under the hood. If empty, do not drive; call for service. For the T5.90, brake pads can be inspected through the wheel openings.
DEF System Malfunction
Common causes
- Low DEF level
- DEF quality issue
- Faulty DEF injector or sensor
What to do
The T5.90 will gradually reduce engine power if DEF is low or contaminated. Refill with fresh DEF fluid. If the light stays on, have the DEF system diagnosed at a New Holland service center.
Frequently Asked Questions
Why does the check engine light come on intermittently on my T5.90?
Intermittent check engine lights are often caused by a loose electrical connection or a temporary emission system fault. On the T5.90, common causes include a faulty EGR sensor or a dirty DPF sensor. Have the codes read at a dealership.
What should I do if the DPF regen light stays on continuously?
If the DPF regeneration light stays on without flashing, the filter may be too clogged to passively clean. On the T5.90, try performing a stationary regeneration by following the prompts on the display. If unsuccessful, dealer service is needed.
How do I reset the service hour meter after an oil change?
On the New Holland T5.90, the service interval is typically reset via the instrument panel menu. Navigate to 'Service' and select 'Reset' after completing the maintenance. Refer to the operator's manual for exact steps.
The hydraulic warning light is on but the hydraulics seem fine – what could it be?
Even if hydraulics appear normal, the warning could indicate low oil level or a blocked filter that hasn't affected performance yet. Check the hydraulic oil dipstick and the filter indicator on the T5.90. Top up if needed.
Can I operate the tractor with the water in fuel light on?
You can continue operation for a short time, but continued use may damage the fuel system. On the T5.90, drain the water separator immediately and replace the fuel filter to prevent injector issues.
What causes the brake system warning light to flash?
A flashing brake warning on the T5.90 typically indicates a fault in the electro-hydraulic braking system. This could be a low brake fluid level or a sensor malfunction. Check fluid and have the system diagnosed promptly.