What is Sany Excavator Fault Code P175?

Fault Code P175 indicates a malfunction in the hydraulic pump pressure sensor circuit or an out-of-range pressure reading detected by the Engine Control Module (ECM). This code is triggered when the ECM receives voltage signals from the hydraulic pump pressure sensor that fall outside the manufacturer's specified parameters, typically indicating either sensor failure, wiring issues, or actual hydraulic system pressure anomalies.

In Sany excavators, the hydraulic pump pressure sensor plays a critical role in monitoring system pressure to optimize engine performance and protect hydraulic components from damage. When this sensor fails to communicate accurate data, the ECM may initiate derate modes or prevent certain hydraulic functions from operating at full capacity. For used equipment, this code often points to sensor degradation or harness wear rather than catastrophic hydraulic failure, making early diagnosis essential to avoid unnecessary downtime and expensive component replacement.

Common Symptoms

When Code P175 is active on your Sany excavator, operators typically experience:

• Hydraulic system warning light illuminated on the instrument cluster, often accompanied by audible alerts
• Reduced hydraulic power or sluggish response in boom, arm, or bucket movements
• Engine derate mode where maximum RPM is limited to protect the system
• Intermittent loss of auxiliary hydraulic functions such as breakers or grapples
• Error messages displayed on the monitor indicating pressure system faults

Potential Causes

Several technical factors commonly trigger P175 in used Sany excavators:

• Hydraulic pump pressure sensor failure due to internal component wear or contamination exposure
• Damaged or corroded wiring harness connections at the sensor plug, particularly where harnesses route near moving components
• ECM communication errors caused by voltage fluctuations or ground circuit problems
• Actual hydraulic system pressure issues including clogged filters, failing pump components, or relief valve malfunctions
• Connector pin corrosion from water intrusion, especially common in machines operating in wet or humid environments
• Previous repair attempts that left loose connections or improperly routed harnesses

How to Troubleshoot and Fix Code P175

Step 1: Visual Inspection and Connector Check Begin by locating the hydraulic pump pressure sensor (typically mounted on the main hydraulic pump assembly). Inspect the sensor and its wiring harness for obvious damage, oil contamination, or corrosion. On used excavators, pay special attention to harness routing near the pump—friction wear against metal surfaces is a common failure point. Disconnect the sensor connector and inspect pins for corrosion, bent terminals, or moisture intrusion.

Step 2: Electrical Testing with Multimeter Using a digital multimeter, perform voltage and resistance checks. With the ignition on and sensor disconnected, check for reference voltage at the harness connector (typically 5 volts). Then measure sensor resistance according to Sany specifications (usually between 200-5000 ohms depending on model). Compare readings against factory specifications found in the service manual or through Sany diagnostic software.

Step 3: Sensor Replacement and Harness Repair If electrical values are out of specification, replace the pressure sensor with a genuine or OEM-equivalent part. Before installation, clean the mounting surface and apply thread sealant as specified. If harness damage is found, repair using proper gauge wire and weatherproof connectors, ensuring the harness is secured away from moving parts and heat sources. After repairs, clear the fault code using diagnostic software and perform a functional test under load.

Step 4: Verify Actual Hydraulic Pressure If the sensor and wiring test normally, connect a mechanical pressure gauge to verify actual system pressure matches sensor readings. Low pressure may indicate pump wear, clogged filters, or relief valve issues requiring hydraulic system service.

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Disclaimer: This guide provides general troubleshooting information for Code P175. Hydraulic and electrical system diagnosis can be complex and potentially dangerous. Always consult your Sany service manual and consider professional assistance from certified technicians, especially when working with high-pressure hydraulic systems on used equipment with unknown service history.