The JLG 600S telehandler dashboard integrates engine, hydraulic, and lift system indicators for operator awareness. Yellow caution lights signal impending issues, while red warnings require immediate action to prevent damage or safety hazards.
JLG 600S Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | A critical system fault, such as engine shut-down or hydraulic failure, demands immediate engine stop on the JLG 600S. | Stop engine safely and consult manual for fault codes. | |
| Master Caution | AMBER | Non-critical system issue detected; the JLG 600S may continue operation but with reduced function or need for service. | Check other warning lights and service as needed. | |
| Check Engine (MIL) | AMBER | Engine control system has detected a fault affecting emissions or performance; the JLG 600S should be serviced soon. | Retrieve diagnostic codes and schedule engine inspection. | |
| Engine Oil Pressure | RED | Engine oil pressure below safe operating level; internal engine damage risk is high if the JLG 600S continues running. | Stop engine immediately and check oil level. | |
| Battery / Charging | RED | Alternator not charging battery or system voltage too low; the JLG 600S may lose electrical power and stall. | Check belt tension and battery connections. | |
| Coolant Temperature | RED | Engine coolant temperature exceeds safe limit; continued operation of the JLG 600S can cause overheating and damage. | Stop engine, allow to cool, check coolant level and fan. | |
| Transmission Temp | AMBER | Transmission fluid temperature is high; the JLG 600S should be operated at reduced load until it cools. | Reduce engine load and allow transmission to cool. | |
| Parking Brake | RED | Parking brake engaged or fault in the brake system; the JLG 600S must not be driven with this light on. | Release parking brake or inspect brake system before moving. | |
| Seat Belt | RED | Operator seat belt not fastened; the JLG 600S may not allow boom or drive functions until belt is buckled. | Fasten seat belt immediately. | |
| Glow Plug / Preheat | AMBER | Engine preheat is active; wait for light to turn off before cranking the JLG 600S in cold conditions. | Wait for light to go out, then start engine. | |
| DPF / Regeneration | AMBER | Diesel particulate filter needs regeneration; run the JLG 600S at high load to initiate automatic cleaning. | Operate machine under load until regeneration completes. | |
| Water in Fuel | AMBER | Water detected in fuel/water separator; drain the filter on the JLG 600S to prevent injector damage. | Drain water from fuel filter housing. | |
| Low Fuel | AMBER | Fuel level is low; refuel the JLG 600S soon to avoid running out and air in system. | Add diesel fuel. | |
| High Beam | BLUE | High-beam headlights are activated for better visibility during JLG 600S operation in dark areas. | Dim when other operators or vehicles are near. | |
| Hydraulic System | RED | Hydraulic system fault, such as low pressure or overheating; lift and drive functions on the JLG 600S may fail. | Stop machine and check hydraulic oil level and temperature. | |
| Fasten Seat Belt | RED | Seat belt not fastened and machine is in motion; the JLG 600S may inhibit travel or lift functions. | Buckle seat belt immediately. | |
| Reduced Power (Limp Mode) | AMBER | Engine or drivetrain fault has limited power to protect the JLG 600S from damage; speed and load reduced. | Service the machine as soon as possible. | |
| Hydraulic Oil | RED | Low hydraulic oil level or excessive temperature; the JLG 600S lift and steering functions may be compromised. | Check hydraulic oil reservoir and add fluid if needed. | |
| Engine Oil Temperature | AMBER | Engine oil temperature is high; reduce load on the JLG 600S to prevent lubrication breakdown. | Reduce engine load and allow oil to cool. | |
| Air Filter | AMBER | Engine air filter is restricted; replace to maintain proper airflow for the JLG 600S engine. | Replace engine air filter. | |
| Service / Hour Meter | AMBER | Scheduled maintenance interval reached; the JLG 600S requires service based on operating hours. | Perform required maintenance per manual schedule. | |
| Work Lights | GREEN | Work lights are illuminated on the JLG 600S for improved visibility around the work area. | Turn off when not needed to conserve battery. | |
| Beacon / Rotating Light | GREEN | Rotating beacon is active, indicating the JLG 600S is operating and increasing awareness. | Ensure beacon is on before machine movement. | |
| Swing / Slew Lock | AMBER | Swing lock is engaged; the upper structure of the JLG 600S cannot rotate until disengaged. | Release swing lock before slewing. | |
| Overload / Capacity | RED | Load exceeds rated capacity; lift and drive functions are disabled to tip the JLG 600S. | Reduce load immediately. | |
| Low Oil Level | RED | Engine oil level is low; add oil to the JLG 600S engine to avoid internal damage. | Check dipstick and add oil. | |
| Brake Fluid Level | RED | Brake fluid level low; braking performance of the JLG 600S may be reduced. | Check brake fluid reservoir and top up. | |
| Door Open | RED | Operator cab door is open; the JLG 600S may not allow travel or lift for safety. | Close door securely. | |
| High Exhaust Temp (HEST) | AMBER | Exhaust temperature elevated during DPF regeneration; keep the JLG 600S away from flammable materials. | Avoid parking near combustibles until temp drops. |
29 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Overload Warning
Common causes
- Exceeding rated load capacity
- Load shifting during operation
- Faulty load sensor
What to do
Immediately reduce load to within rated capacity. If light persists, calibrate load sensing system on the JLG 600S per service manual.
Engine Low Oil Pressure
Common causes
- Low engine oil level
- Clogged oil filter
- Oil pump failure or worn bearings
What to do
Stop engine instantly. Check oil level and add if low. If oil level is fine, do not restart; tow to service for oil pressure diagnosis - common in JLG 600S due to high hours.
Hydraulic System Overheat
Common causes
- Continuous heavy lifting in hot ambient
- Low hydraulic oil level
- Clogged hydraulic oil cooler
What to do
Allow the JLG 600S to idle with controls neutral to circulate and cool oil. Check hydraulic oil reservoir and inspect cooler fins for debris.
DPF Regeneration Fault
Common causes
- Frequent low-load operation preventing passive regen
- Failed exhaust temperature sensor
- Excessive ash accumulation in filter
What to do
Run the JLG 600S at high engine speed under moderate load for 20-30 minutes to force active regeneration. If light remains, have DPF serviced or replaced by dealer.
Brake System Malfunction
Common causes
- Low brake fluid level
- Worn brake pads
- Hydraulic brake leak
What to do
Park the JLG 600S on level ground, engage parking brake, and check brake fluid reservoir. If low, fill with DOT 4 fluid and check for leaks before moving.
Frequently Asked Questions
What does the Master Warning (Stop) light mean on my JLG 600S?
The red master warning light indicates a critical system failure, such as engine shutdown or hydraulic fault. Stop the engine immediately and refer to the fault code display (if equipped) to identify the issue before restarting.
How do I reset the DPF regeneration light on the JLG 600S?
The DPF light resets automatically after a successful regeneration. To trigger regeneration, operate the JLG 600S under moderate to heavy load (such as lifting near capacity) at high engine RPM for 20-30 minutes. If it doesn't clear, the filter may need service.
What should I do if the Overload light comes on while lifting?
Immediately stop lifting and lower the load to the ground. The JLG 600S will disable lift and drive functions until the load is reduced below rated capacity. Check the load chart for correct capacity at your boom angle and extension.
Why is my Low Fuel light on even after refueling the JLG 600S?
The fuel level sensor may be stuck or the tank may not be full. Try turning the ignition off and on. If it persists, the sensor or wiring may need inspection, but refueling to calm the warning is common on these models.
How often does the JLG 600S need a service reminder reset?
The hour-meter service light activates at intervals specified in the operator manual (typically every 250 hours). After performing the required service (oil, filters, etc.), reset the light by pressing the hour meter reset button or using the diagnostic menu.