The Caterpillar 308 is a compact excavator known for its robust performance, advanced hydraulics, and intuitive operator controls. Its instrument cluster provides essential alerts to maximize uptime and prevent costly repairs in challenging jobsite conditions.
Caterpillar 308 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | A critical fault has been detected in the Caterpillar 308, requiring you to stop the machine immediately. | Safely park and shut down the excavator; investigate the source of the warning before restarting. | |
| Master Caution | AMBER | A non-critical system issue has been detected on the 308, which may affect performance if not addressed soon. | Check the display for further information and schedule necessary servicing. | |
| Check Engine (MIL) | AMBER | The engine management system on your 308 has identified a fault affecting emissions or performance. | Inspect for error codes using the onboard diagnostics and contact your CAT dealer if the issue persists. | |
| Engine Oil Pressure | RED | Engine oil pressure has dropped below safe levels on the 308, risking severe engine damage. | Shut down the engine immediately and check oil level and condition before restarting. | |
| Battery / Charging | RED | The charging system is malfunctioning, and the 308's battery is not recharging during operation. | Inspect alternator connections and battery terminals; do not operate until the issue is resolved. | |
| Coolant Temperature | RED | The engine coolant temperature has exceeded safe limits in your 308, risking overheating. | Stop the machine, allow engine to cool, and inspect coolant level and radiator for blockages. | |
| Hydraulic System | AMBER | A fault has been detected within the 308's hydraulic system, possibly affecting digging power or control. | Check hydraulic fluid level and look for leaks; schedule service if the light remains on. | |
| Low Fuel | AMBER | The fuel level in the 308's tank is low, and continued operation may soon be interrupted. | Refuel at the next opportunity to avoid running out of diesel on site. | |
| Hydraulic Oil | AMBER | Hydraulic oil level or pressure is below normal in your 308, which can reduce system efficiency. | Check and top up hydraulic oil, and inspect for leaks if the warning persists. | |
| Engine Oil Temperature | RED | Engine oil temperature has reached a critical threshold in the 308, endangering engine integrity. | Stop operation, let engine cool, and verify oil level and cooling system function. | |
| Air Filter | AMBER | The air filter on the 308 is clogged or restricted, potentially reducing engine power. | Inspect and clean or replace the air filter element to restore airflow. | |
| Fuel Filter / Water Separator | AMBER | The 308's fuel filter is clogged or water has been detected in the separator. | Drain water from the separator or replace the filter as soon as possible. | |
| Service / Hour Meter | AMBER | Scheduled service is due on your Caterpillar 308 based on engine hours. | Arrange for maintenance according to the interval shown to keep the 308 running reliably. | |
| Work Lights | BLUE | The 308's work lights are switched on, illuminating the work area for better visibility. | No action required unless lights are not needed; switch off to conserve battery. | |
| Beacon / Rotating Light | AMBER | The rotating beacon is active, signaling the 308's presence for jobsite safety. | No action required unless beacon use is not necessary per site rules. | |
| Swing / Slew Lock | AMBER | The swing lock is engaged, preventing the 308's upper structure from rotating. | Disengage the swing lock before attempting to slew the machine. | |
| Overload / Capacity | RED | The 308 has detected a load beyond its rated capacity, risking stability or damage. | Lower the load immediately and reassess lifting strategy to stay within rated limits. | |
| Door Open | AMBER | A cab or access panel door is open on the 308, which may be unsafe during operation. | Secure all doors and panels before continuing work. | |
| High Exhaust Temp (HEST) | AMBER | The exhaust temperature is elevated during a regeneration event on the 308. | Keep the area around the exhaust clear and avoid parking near flammable materials. | |
| DPF / Regeneration | AMBER | The 308's diesel particulate filter is actively regenerating to burn off soot. | Allow the regeneration cycle to complete without interruption for optimal emissions control. | |
| DEF / AdBlue | AMBER | Diesel Exhaust Fluid (DEF) level is low or there is a fault in the DEF system on the 308. | Refill DEF tank and check for system errors to maintain emissions compliance. | |
| Water in Fuel | AMBER | Water has been detected in the 308's fuel system, risking injector or pump damage. | Drain the water separator promptly and monitor for recurring contamination. | |
| Parking Brake | RED | The parking brake is applied on the 308, preventing movement. | Release the parking brake before attempting to drive or reposition the machine. | |
| Fasten Seat Belt | AMBER | The operator seat belt is not fastened on the 308, which is a critical safety step. | Buckle the seat belt before operating the excavator. | |
| Glow Plug / Preheat | AMBER | The glow plugs are active, preheating the 308's engine for cold starting. | Wait for the light to go out before cranking the engine in cold conditions. |
25 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Engine Oil Pressure
Common causes
- Low engine oil level
- Oil pump failure
- Oil filter blockage
What to do
Immediately stop the 308, check for oil leaks or a low dipstick reading, and top up with the correct oil type. If pressure does not recover, contact a Caterpillar service technician.
Coolant Temperature
Common causes
- Low coolant level
- Radiator blockage
- Faulty thermostat
What to do
Let the engine cool down, then inspect the coolant reservoir and radiator for obstructions or leaks. Add coolant if needed and seek professional help if the issue repeats.
Overload / Capacity
Common causes
- Lifting beyond rated load
- Incorrect lift point or attachment
- Uneven ground conditions
What to do
Safely lower the load and reassess the lifting configuration. Always use the 308 within its published lift charts and ensure firm, level ground before attempting heavy lifts.
Battery / Charging
Common causes
- Failed alternator
- Loose or corroded battery cables
- Worn drive belt
What to do
Inspect all battery and alternator connections, clean and tighten as needed, and replace the alternator or belt if charging voltage remains low.
Hydraulic System
Common causes
- Low hydraulic oil
- Hydraulic leak
- Pump or hose failure
What to do
Check the hydraulic oil level and refill if low. Inspect hoses and connections for leaks, and if unresolved, have a CAT technician diagnose the hydraulic system.
Frequently Asked Questions
What should I do if the DPF regeneration light stays on in my 308?
Make sure engine RPM is above idle and keep operating under load to allow regeneration to finish; if the light won't clear, contact your CAT dealer for assistance.
Can I operate the 308 if the hydraulic warning light is on but performance seems normal?
You should check fluid levels and look for leaks; continued operation with the warning on may lead to more severe damage even if performance appears unaffected.
How often does the 308 require scheduled maintenance?
Follow the hour meter and service indicator; most routine maintenance intervals are every 250 or 500 hours, but consult your operator's manual for model-specific schedules.
What does it mean if the DEF/AdBlue light comes on?
This indicates low DEF level or a possible system fault; refill the DEF tank with the correct fluid and check for further warnings.
Why is the air filter light illuminated after replacing the filter?
The air filter indicator may need to be reset; consult the 308's manual for the reset procedure or verify that the new filter is properly installed and seated.
Is it safe to operate the 308 with the swing lock engaged?
No, the swing lock prevents upper carriage rotation; disengage it before attempting to swing the machine to avoid damage.