What is Doosan DX150LC-9C Fault Code E000105-05?

Fault Code E000105-05 indicates a Pilot Pressure Sensor Circuit Low Voltage condition on the Doosan DX150LC-9C excavator. This code is triggered when the Electronic Control Module (ECM) detects an abnormally low voltage signal from the pilot pressure sensor, which monitors the hydraulic pilot pressure used to control excavator functions.

The pilot pressure sensor is critical for the DX150LC-9C's electro-hydraulic control system. It provides real-time feedback to the ECM about pilot circuit pressure, allowing precise control of boom, arm, bucket, and swing functions. When voltage drops below the manufacturer's specified threshold (typically below 0.5V), the ECM logs this fault code and may limit machine performance to prevent hydraulic system damage. For used excavators, this code often points to wiring degradation or sensor wear rather than catastrophic failures.

Common Symptoms

When Code E000105-05 is active, operators typically experience:

• Illuminated warning light on the instrument cluster, often accompanied by an audible alarm
• Reduced hydraulic responsiveness or sluggish joystick controls across multiple functions
• Intermittent loss of pilot control, particularly during cold starts or after extended operation
• Machine entering derate mode, limiting engine RPM or hydraulic flow to protect systems
• Error message display on the monitor panel specifically referencing pilot pressure system faults

Potential Causes

The most common technical causes for this fault code on used DX150LC-9C excavators include:

• Damaged or corroded wiring harness connections at the pilot pressure sensor, especially where harnesses route near the hydraulic tank or cab pivot point
• Failed pilot pressure sensor due to internal component degradation, diaphragm failure, or contamination from hydraulic fluid
• Shorted or broken sensor signal wire caused by harness chafing against sharp edges or vibration-induced fatigue
• Corroded connector pins at the sensor plug or ECM connection points, common in machines exposed to moisture or harsh environments
• Poor ground connection affecting the sensor's reference voltage circuit
• ECM internal fault (rare) affecting the sensor input circuit processing

How to Troubleshoot and Fix Code E000105-05

Step 1: Visual Inspection Begin by inspecting the pilot pressure sensor located near the hydraulic pilot filter assembly. Check for physical damage, fluid contamination on the connector, or corroded terminals. On used excavators, carefully trace the sensor harness along its entire route, looking for wear points where insulation may have rubbed through against metal brackets or hydraulic lines.

Step 2: Electrical Testing Using a digital multimeter (DMM), disconnect the sensor connector and measure resistance between the sensor terminals. Compare readings against Doosan specifications (typically 200-500 ohms depending on sensor type). Next, check the signal wire voltage at the ECM connector with the key on, engine off—it should read approximately 5V reference voltage. Measure ground continuity between the sensor ground pin and chassis ground (should be less than 1 ohm).

Step 3: Signal Wire and Connector Testing Perform a voltage drop test on the signal wire while wiggling the harness to identify intermittent shorts or opens. Inspect connector pins for corrosion, bent terminals, or moisture intrusion—common issues on used machines. Clean connections with electrical contact cleaner and apply dielectric grease.

Step 4: Sensor Replacement and Verification If electrical testing confirms proper voltage and ground but the sensor resistance is out of specification, replace the pilot pressure sensor with a genuine Doosan part. After replacement, clear fault codes using Doosan DMS (Diagnostic Monitoring System) software or a compatible diagnostic tool, then perform a function test of all hydraulic controls.

Critical for Used Excavators: Before replacing expensive components, thoroughly inspect harness routing and protection. Many E000105-05 codes on older DX150LC-9C machines result from harness abrasion near the cab swivel area or hydraulic tank mounting points where vibration causes wire fatigue.

---

Disclaimer: This guide provides general troubleshooting information for educational purposes. Always consult the official Doosan service manual for your specific serial number and seek assistance from certified Doosan technicians for complex repairs. Improper diagnostics can lead to equipment damage or safety hazards.