What is Doosan DX215-9C Fault Code E520801-12 (P1017)?

Fault Code E520801-12 (P1017) on the Doosan DX215-9C excavator indicates a Turbocharger Boost Pressure Sensor Circuit Low Voltage condition. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormally low voltage signal from the boost pressure sensor circuit, typically below 0.5 volts for more than 2 seconds during engine operation.

The boost pressure sensor monitors the air pressure generated by the turbocharger and sends critical data to the ECM for optimal fuel injection timing and engine performance. On the DX215-9C's Doosan DL06 engine, this sensor is essential for maintaining proper air-fuel ratios and preventing engine damage from over-boost or under-boost conditions. When this code activates, the ECM enters a default mode that can significantly impact machine productivity.

Common Symptoms

• Yellow warning light illuminated on the instrument cluster with reduced engine power output
• Engine derate mode activated, limiting maximum RPM to approximately 1,800-2,000 RPM
• Black smoke from the exhaust due to improper fuel-to-air mixture during load conditions
• Poor throttle response and sluggish hydraulic function, especially during combined operations
• Stored fault code in ECM memory that requires diagnostic software to clear even after repair

Potential Causes

The most common technical failures causing this code on used DX215-9C excavators include:

• Damaged or corroded sensor connector at the turbocharger mounting location (prone to heat and moisture exposure)
• Broken signal wire in the harness between the ECM and boost sensor, particularly at harness routing points near the engine mount brackets
• Failed boost pressure sensor due to internal diaphragm rupture or electronic component degradation (common after 6,000+ operating hours)
• Poor ground connection at the sensor or ECM chassis ground points due to corrosion buildup
• ECM internal circuit failure (rare, but possible in machines with electrical system history)
• Aftermarket sensor incompatibility if previous repairs used non-OEM parts

How to Troubleshoot and Fix Code E520801-12 (P1017)

Step 1: Visual Inspection Locate the boost pressure sensor on the intake manifold near the turbocharger outlet. Inspect the 3-pin connector for corrosion, bent pins, or oil contamination. Check the wire harness for obvious damage, particularly where it routes across the engine valley and near moving components. On used excavators, pay special attention to harness chafing points against engine covers.

Step 2: Electrical Testing Using a digital multimeter, perform a voltage check at the sensor connector with the ignition ON, engine OFF. You should measure approximately 5 volts on the reference voltage wire (typically the red/white wire). Check for proper ground continuity (less than 1 ohm resistance) on the black ground wire. Measure the signal wire voltage; it should read between 0.5-4.5 volts depending on atmospheric pressure.

Step 3: Sensor and Circuit Verification Disconnect the sensor and measure its internal resistance between the signal and ground pins (should be 1,000-3,000 ohms at room temperature). If readings are out of specification, replace the sensor with a genuine Doosan part (Part #2871960900). If sensor tests good, perform a harness continuity test from the ECM connector to the sensor, checking for short circuits to ground or open circuits. Use Doosan DMS diagnostic software to monitor live sensor data and compare readings to atmospheric pressure baseline values.

Step 4: Final Verification After repairs, clear the fault code using diagnostic software, start the engine, and allow it to reach operating temperature. Perform a snap throttle test and monitor boost pressure readings. Values should increase from approximately 100 kPa (atmospheric) to 150-200 kPa under load conditions.

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Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Doosan service manual for your specific machine serial number and software version. If you lack proper diagnostic tools or experience with high-pressure fuel systems, consult a certified Doosan technician to prevent injury or further machine damage.