The MAN 18.440 is a heavy-duty semi truck designed for long-haul transport, featuring a 440 hp engine and advanced electronics. Its instrument cluster uses intuitive warning lights to alert drivers to potential issues, ensuring safe and efficient operation. Understanding these symbols helps prevent costly breakdowns and maintains vehicle reliability.
MAN 18.440 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Check Engine | AMBER | Indicates an emissions-related malfunction or engine fault specific to the MAN 18.440's D20 Common Rail engine. | Reduce load and drive to a service center; avoid prolonged high RPM operation. | |
| Engine Oil Pressure | RED | Low oil pressure detected in the MAN 18.440's lubrication system, risking severe engine damage. | Stop the engine immediately and check oil level; do not restart until resolved. | |
| Battery / Charging | RED | Charging system fault on the MAN 18.440, possibly due to alternator or battery failure. | Turn off non-essential electrical loads and drive to nearest service point; if red persists, stop engine. | |
| Coolant Temperature | RED | Engine coolant temperature exceeds safe limits in the MAN 18.440, risking overheating and damage. | Stop engine, let it cool, check coolant level and fan operation; do not open hot radiator. | |
| Brake System | RED | Fault in the MAN 18.440's air brake system, including possible air leakage or brake wear. | Stop safely and check air pressure; do not drive until brake function is verified. | |
| ABS | AMBER | Antilock Braking System malfunction on the MAN 18.440; standard braking still works but without ABS. | Drive to service center; avoid emergency braking situations. | |
| Parking Brake | RED | Parking brake is engaged or a fault exists in the MAN 18.440's spring brake system. | Ensure parking brake is fully released before driving; if light stays on, check brake chambers. | |
| Glow Plug / Preheat | AMBER | Glow plug preheating is active or a fault in the MAN 18.440's cold start system. | Wait for light to go out before starting; if flashing, have glow plugs inspected. | |
| DEF / AdBlue | AMBER | AdBlue level low or system fault in the MAN 18.440's SCR emission control; may reduce engine power. | Top up AdBlue as soon as possible; if fault persists, visit service center. | |
| Water in Fuel | AMBER | Water detected in the fuel filter of the MAN 18.440, which can damage the injection system. | Drain water from the fuel filter separator; if light remains, replace filter. | |
| Low Fuel | AMBER | Fuel level in the MAN 18.440's tanks is low; refuel to avoid running out. | Refuel at the next opportunity; do not let tank run dry to prevent air in system. | |
| High Beam | BLUE | High beam headlights are activated on the MAN 18.440. | Dim when approaching oncoming traffic to avoid glare. | |
| Power Steering (EPS) | AMBER | Electronic power steering system fault on the MAN 18.440; steering may become heavy. | Drive to service center; avoid sudden maneuvers if steering feels heavy. | |
| Air Brake Pressure (Low) | RED | Air pressure in the MAN 18.440's brake system is below safe operating level. | Stop immediately and allow air pressure to build; do not drive until pressure is normal. | |
| Engine / Exhaust Brake | GREEN | Retarder or exhaust brake is active on the MAN 18.440, aiding downhill speed control. | Use as needed for braking assistance; no immediate action required. | |
| High Exhaust Temp (HEST) | AMBER | Exhaust system temperature is high during DPF regeneration on the MAN 18.440. | Normal during regeneration; avoid parking near flammable materials. |
16 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Oil Pressure Warning
Common causes
- Low oil level
- Oil pump failure
- Clogged oil filter
What to do
Stop the engine immediately on the MAN 18.440 and check oil level. If full, have the oil pump and filter inspected by a MAN dealership.
Coolant Overheat
Common causes
- Low coolant level
- Faulty thermostat
- Radiator blockage
What to do
Pull over safely and let the MAN 18.440 engine cool. Check coolant level and fan operation; if low, add approved coolant. If problem persists, tow to service.
Air Brake System Failure
Common causes
- Air leak in lines
- Faulty compressor
- Moisture in air tanks
What to do
Stop the MAN 18.440 and listen for air leaks. Check air pressure gauge; if unable to build pressure, call for roadside assistance. Do not drive without proper brakes.
Charging System Failure
Common causes
- Alternator belt broken
- Alternator failure
- Battery terminal corrosion
What to do
Turn off unnecessary electrical loads and drive the MAN 18.440 to the nearest workshop. If the battery warning stays red, stop and have the alternator checked.
Check Engine / Emissions
Common causes
- Faulty sensor
- DPF clogged
- AdBlue system issue
What to do
The MAN 18.440 may enter limp mode; reduce speed and schedule service. If the light flashes, stop immediately to prevent catalytic converter damage.
Frequently Asked Questions
Why is my MAN 18.440's check engine light on with reduced power?
This often indicates a DPF regeneration or AdBlue system issue specific to the MAN 18.440's D20 engine. Try performing a stationary regeneration if safe, otherwise service is needed.
How do I reset the service interval light on a MAN 18.440?
The service light is reset by a certified MAN technician using diagnostic software. Attempting manual reset may not work; follow the maintenance schedule.
What does the amber brake system light mean on my MAN 18.440?
It could be a warning of brake pad wear or a minor air pressure drop. Monitor air pressure gauges; if the red brake warning also comes on, stop immediately.
Can I drive my MAN 18.440 with the AdBlue light on?
Yes, but only for a limited distance. On the MAN 18.440, if AdBlue runs out, engine power will be reduced and eventually the engine will not restart. Top up as soon as possible.
Why does my MAN 18.440's exhaust brake light flash?
A flashing exhaust brake light indicates a fault in the system. It may be caused by a sensor or actuator issue. Have it checked during next service.