What is Doosan Excavator Fault Code E000110-15?

Fault Code E000110-15 indicates a malfunction in the engine coolant temperature sensor circuit, specifically detecting an abnormal voltage signal or intermittent connection within the cooling system monitoring network. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) receives voltage readings outside the predetermined parameters (typically below 0.3V or above 4.8V) from the coolant temperature sensor.

This code is critical for Doosan excavators because the ECM relies on accurate coolant temperature data to optimize fuel injection timing, regulate engine protection systems, and control the cooling fan operation. When E000110-15 is active, the engine management system may default to predetermined "limp mode" values, potentially causing inefficient combustion, increased fuel consumption, and inadequate overheating protection on aging machines.

Common Symptoms

• Engine warning light illuminated on the instrument cluster, often accompanied by a coolant temperature gauge reading abnormally low (below 60°F) or pegged at maximum
• Cooling fan running continuously at high speed, even during cold starts or low-load operations
• Reduced engine power or derate mode activation, limiting hydraulic performance and cycle times
• Hard starting conditions when the engine is warm, as the ECM incorrectly calculates fuel delivery
• Increased white or black exhaust smoke due to improper fuel-to-air mixture from faulty temperature compensation

Potential Causes

The most common technical failures causing E000110-15 on used Doosan excavators include:

• Coolant temperature sensor degradation from prolonged heat cycling, causing internal resistance drift or complete element failure
• Wiring harness damage at known rub points near the engine block mounting brackets or along the frame rail where vibration causes insulation wear
• Corroded or loose connector terminals at the sensor plug, particularly on machines operated in high-moisture or marine environments
• ECM internal circuit failure (less common) affecting the 5-volt reference voltage supply to the sensor
• Coolant contamination causing sensor element coating or electrical pathway interference in machines with poor maintenance history

How to Troubleshoot and Fix Code E000110-15

Step 1: Connect a Doosan DMS diagnostic software or compatible scan tool to retrieve freeze frame data and verify the code is current, not historical. Note the coolant temperature reading displayed versus actual engine temperature.

Step 2: Locate the coolant temperature sensor (typically threaded into the thermostat housing or cylinder head). Disconnect the sensor harness connector and inspect for corrosion, bent pins, or moisture intrusion—common issues on used excavators with 3,000+ operating hours.

Step 3: Using a digital multimeter, measure sensor resistance at ambient temperature (approximately 2,000-3,000 ohms at 68°F for most Doosan applications). Compare readings against manufacturer specifications. Test the ECM supply voltage at the harness side (should read approximately 5 volts with key on, engine off).

Step 4: Inspect the wiring harness from sensor to ECM for chafing, especially where it passes over engine mounting points. On used machines, check for previous repair attempts using improper wire gauge or insulation tape that may have degraded.

Step 5: If sensor and wiring test within specifications, perform a heat soak test by warming the sensor in water while monitoring resistance values—failures often appear only at operating temperature. Replace the sensor if resistance doesn't decrease predictably with temperature increase.

Step 6: Clear codes, operate the machine through a complete warm-up cycle, and verify repair with diagnostic software.

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Disclaimer: This guide provides general diagnostic information. Always consult the official Doosan service manual for your specific model and serial number range. Complex electrical issues may require professional diagnosis with OEM-level diagnostic equipment.