High Coolant Temperature Emergency Shutdown
The PERKINS-110-0 (Kohler RDC2) diesel fault code means: High Coolant Temperature Emergency Shutdown. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- moderate
- Estimated cost
- DIY coolant top-up or belt replacement: $20-$80 in parts. Thermostat replacement (DIY-moderate): $40-$120 in parts. Professional diagnosis and repair: $200-$900 depending on root cause. Water pump replacement by a shop: $400-$1,200 on larger Perkins frames. Head gasket repair if overheating caused internal damage: $1,500-$4,000 or more.
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Common Symptoms
- Engine shuts down abruptly and displays fault code 110-0 on the PowerWizard 1.1/2.0 controller panel
- Red shutdown lamp illuminates on the control panel
- Generator output drops to zero and load is dropped without a soft transfer
- Coolant temperature gauge reads in the red zone before shutdown, typically above 105 degrees C
- Coolant overflow tank may show bubbling or have expelled coolant onto the floor around the genset
- Engine will not restart after the fault until the unit has cooled and the fault is manually reset
- ATS fails to transfer load back to generator if utility power is unavailable, leaving site without power
Probable Causes (Ranked by Likelihood)
- Low coolant level due to a leak or slow seep at hose clamps, radiator, or water pump seal Very Likely
- Radiator fins blocked by dirt, debris, insects, or lagging insulation restricting airflow Very Likely
- Cooling fan belt broken or slipping, reducing fan speed and airflow through the radiator Likely
- Faulty or stuck-closed thermostat preventing coolant from circulating through the radiator Likely
- Failed water pump impeller not circulating coolant through the block and radiator Possible
- Defective coolant temperature sensor sending a false high reading to the ECM Possible
- Ambient temperature in the generator enclosure or room far exceeding design limits, starving the radiator of cool intake air Less Likely
Step-by-Step Diagnostic Procedure
Step 1 -- Safety first. Do NOT remove the radiator cap or any coolant hoses while the engine is hot. Wait at least 30 minutes after shutdown before touching the cooling system. Pressurized hot coolant causes severe burns.
Step 2 -- Check the coolant level. Once the engine is cool, remove the radiator cap slowly and inspect the level. It should be within 25 mm of the filler neck. Also check the overflow or degas bottle. If it is empty or the coolant is visibly dirty or rusty, you have found a leading cause.
Step 3 -- Inspect all coolant hoses and clamps for wetness, mineral deposits (white or orange crust), or soft/swollen hose material. Run your hand along the bottom of hoses and around the water pump housing. Any dampness is a leak.
Step 4 -- Check the radiator core and fins. Stand in front of the radiator and look straight through it. You should see daylight through the fins. If the fins are packed with dirt, grass, or debris, clean them gently with low-pressure compressed air or a hose from the engine side outward. Do not use a pressure washer, which will bend the fins.
Step 5 -- Inspect the fan belt (if equipped with a belt-driven fan). With the unit off and all guards replaced, check belt tension by pressing firmly on the longest run of the belt. It should deflect no more than 10-15 mm. A loose or cracked belt needs replacement. Note: many Perkins 1100 and 1300 series use a poly-V belt. Cracks on the ribbed side indicate imminent failure.
Step 6 -- Check if the fault is real or a sensor issue. If the coolant level, hoses, belt, and radiator all look normal, the temperature sensor (located on the thermostat housing or engine block) may be faulty. With a multimeter set to resistance (ohms), unplug the sensor connector and measure resistance across the two sensor terminals. At room temperature (25 degrees C) a typical Perkins NTC sensor reads approximately 2,000 to 2,500 ohms. A reading of zero ohms (short) or open circuit (infinite) means replace the sensor. This step is as far as you should go without Perkins EST or a dealer scan tool.
Step 7 -- Check enclosure ventilation. Confirm that the louvres or ventilation openings on the generator room or canopy are not blocked. The generator needs a clear path for cool air in and hot air out. If the room feels extremely hot even 30 minutes after shutdown, insufficient airflow is a contributing cause.
Step 8 -- Reset and retest. After correcting any obvious issue, reset the fault on the PowerWizard controller by pressing and holding the STOP button or navigating to the fault menu and selecting RESET. Start the engine in MANUAL mode and watch the coolant temperature reading on the controller display climb. It should stabilize between 85 and 95 degrees C under load. If it climbs past 100 degrees C and keeps rising, stop the engine and call a certified Perkins or FG Wilson technician. Do not run the engine into another shutdown.
Common Fixes by Vehicle
What techs usually find when diagnosing PERKINS-110-0 on specific platforms — tap a platform for the fix and the exact part:
Perkins 1103D / 1104D / 1106D industrial gensets Moderate DIY
Perkins SPN 110 FMI 0 (High Coolant Temperature Shutdown) on outdoor genset packages is most often radiator fouling -- dust, cottonwood seed, and grass clippings accumulate on the radiator core and reduce airflow. Clean the radiator fins from the fan side with a low-pressure water rinse (do not use high pressure -- it bends fins). Verify coolant level and concentration (50/50 minimum). If the radiator is clean, suspect the thermostat ($40-$80) before the water pump.
Labor: 1-2 hoursFrequently Asked Questions
What does Perkins code 110-0 mean on my FG Wilson generator?
Code 110-0 means the engine coolant temperature climbed past the maximum safe limit, typically around 105 degrees C, and the ECM shut the engine down automatically to prevent serious damage to the cylinder head, head gasket, and pistons. It is not a sensor glitch. The engine genuinely got too hot and needs to be inspected before you restart it.
Can my generator still run with this code active?
No. Code 110-0 is a hard shutdown fault. The PowerWizard controller locks out the starter until you manually reset the fault. Even after a reset, if you restart without fixing the underlying cause, the engine will overheat again and shut down, potentially causing expensive internal damage.
How much does it cost to fix a 110-0 fault?
It depends on the root cause. If you just need to top up coolant and tighten a hose clamp, materials cost under $30 and you can do it yourself. A new thermostat or fan belt is $40 to $150 in parts. If a water pump or radiator needs replacement on a larger FG Wilson frame, expect a shop bill of $600 to $1,500. If the engine ran hot long enough to blow a head gasket, repairs can exceed $3,000 to $4,000.
Will the generator start the next time the power goes out?
Not until the fault is reset AND the root cause is corrected. If utility power fails and you try to start the generator with a 110-0 fault still active in the controller, the unit will not crank. Even if you reset the fault without fixing the problem, the engine will likely shut down again within minutes once it reaches operating temperature. Fix the cooling system issue first, then verify a clean test run before relying on the genset.