The Yanmar Tractor YM347 is a compact utility tractor designed for mowing and light agricultural tasks. Its instrument cluster provides essential warnings to monitor engine, hydraulic, and transmission health. Understanding these indicators ensures safe operation and prevents costly repairs.
Yanmar Tractor YM347 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | This red stop symbol illuminates when a critical engine or system fault is detected on your YM347, such as low oil pressure or engine overheat. | Stop the tractor immediately, turn off the engine, and check the YM347's operator's manual for specific fault codes. | |
| Check Engine (MIL) | AMBER | Glows amber when the YM347's electronic control unit (ECU) detects an emission or engine management issue, often related to fuel or sensor problems. | Reduce load and continue operation if no drivability loss; schedule service at a Yanmar dealer to read diagnostic trouble codes. | |
| Engine Oil Pressure | RED | Indicates low engine oil pressure in your YM347's 3-cylinder diesel engine, which can cause severe internal damage if ignored. | Immediately shut off the engine, check oil level with the dipstick, and add SAE 10W-30 oil if low; if light persists, do not restart and tow to a shop. | |
| Battery / Charging | RED | Lights when the YM347's alternator is not charging the battery or voltage is too low, often due to a loose belt or failed alternator. | Check the alternator belt tension on your YM347; if belt is fine, have the charging system tested by a technician. | |
| Coolant Temperature | RED | Illuminates red when the YM347's engine coolant exceeds safe operating temperature, typically above 230°F, risking head gasket failure. | Stop the tractor, let it cool, check coolant level in the overflow tank, and inspect for leaks or a stuck thermostat. | |
| Glow Plug / Preheat | AMBER | Amber indicator that activates during cold starts on the YM347, showing the glow plugs are heating the combustion chambers for easier ignition. | Wait for this light to turn off before cranking the engine; if it stays on longer than 10 seconds, glow plug relay may need inspection. | |
| Low Fuel | AMBER | Warns that the YM347's fuel level is low, helping you avoid running out of diesel and needing to bleed the fuel system. | Refuel with clean #2 diesel as soon as possible; never let the tank run dry to prevent air ingress. | |
| PTO Engaged | GREEN | Green light confirms the YM347's power take-off (PTO) shaft is engaged and rotating, typically used for mower decks or implements. | Ensure all bystanders are clear before operating PTO; disengage when not in use to save fuel and reduce wear. | |
| Parking Brake | RED | Red lamp indicates the YM347's parking brake is applied; it will flash if you attempt to drive with the brake engaged. | Release the parking brake fully before moving; if light stays on, check brake linkage adjustment. | |
| Service / Hour Meter | AMBER | Amber service reminder that illuminates every 100 hours on the YM347 to prompt oil change, filter replacement, and general inspection. | Perform scheduled maintenance per the YM347 owner's manual; reset the light after service by following the manual procedure. | |
| Hydraulic Oil | AMBER | Warns of low hydraulic oil level or high temperature in the YM347's hydraulic system, affecting loader and three-point hitch performance. | Check hydraulic fluid level in the rear reservoir and add Yanmar hydraulic fluid if low; inspect for leaks at hoses and cylinders. | |
| Water in Fuel | AMBER | Alerts that water has accumulated in the YM347's fuel filter/water separator, which can cause injector damage and poor running. | Drain the water from the fuel filter bowl immediately; replace the filter if sediment is excessive. |
12 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Engine Overheat
Common causes
- Coolant leak from radiator or hoses
- Failed thermostat stuck closed
- Radiator fins clogged with debris
What to do
On your YM347, stop the engine, let it cool, then clean the radiator core with compressed air from behind. Check coolant level and refill with a 50/50 mix of water and ethylene glycol antifreeze. Replace thermostat if problem persists.
Fuel System Air Lock
Common causes
- Running out of diesel
- Leaky fuel line connection
- Clogged fuel filter
What to do
For a YM347, purge air by loosening the injection pump bleed screw and cranking until steady fuel flows. Tighten screw, then start engine. Replace fuel filter if contaminated.
Low Engine Oil Pressure
Common causes
- Low oil level due to consumption or leak
- Oil filter clogged
- Worn engine bearings
What to do
Immediately stop the YM347. Use dipstick to verify oil level; add 10W-30 diesel oil if low. If level is normal, replace the oil filter and check for bearing wear at a dealer.
Hydraulic System Failure
Common causes
- Low hydraulic fluid level
- Hydraulic pump cavitation
- Filter blockage
What to do
Check the hydraulic reservoir on the YM347; fill with Yanmar hydraulic fluid to the full mark. Clean or replace the hydraulic return filter. If pump noise persists, inspect for suction line leaks.
Frequently Asked Questions
Why does the 'Glow Plug' light stay on for a long time in my YM347?
If the glow plug indicator stays illuminated for over 10 seconds on your YM347, the glow plug relay may be faulty, or one or more glow plugs have failed. Replace glow plugs and the relay as a set for reliable cold starts.
Can I mow with the 'Check Engine' light on?
You can continue mowing at reduced load if the engine runs smoothly, but have the YM347's ECU scanned soon. A persistent light often indicates a sensor or emission issue that may worsen over time.
How do I reset the service hour meter light?
To reset the YM347's service light after an oil change, turn the key to 'ON', press and hold the hour meter reset button until the light flashes three times, then release. Refer to the manual for exact procedure.
What does the 'Water in Fuel' light mean and how urgent is it?
This warning indicates water has collected in the YM347's fuel filter bowl. It is moderately urgent because water can damage injection pump and injectors. Drain the water separator immediately using the valve at the bottom of the filter housing.
Why is my battery light dimly lit while running?
A dim battery light on the YM347 often signals a weak alternator or poor connection. Check the alternator drive belt tension first; if okay, test charging voltage at the battery (should be 13.5-14.5V). Clean battery terminals if corroded.