What is Komatsu PC160LC-7 Fault Code E215?

Komatsu PC160LC-7 fault code E215 indicates a malfunction in the swing motor secondary pressure sensor circuit. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects an abnormal voltage signal from the pressure sensor that monitors hydraulic pressure in the swing motor's secondary circuit.

The swing motor secondary pressure sensor plays a critical role in the PC160LC-7's hydraulic management system. It provides real-time feedback to the controller, allowing the machine to optimize swing performance, prevent overload conditions, and protect hydraulic components from excessive pressure. When this sensor circuit fails, the excavator's intelligent hydraulic control system cannot accurately regulate swing functions, potentially leading to reduced productivity and component damage.

Common Symptoms

When fault code E215 is active on your Komatsu PC160LC-7, operators typically experience:

• Swing function warning light illuminated on the instrument cluster
• Erratic or inconsistent swing speed and acceleration performance
• Reduced swing torque, particularly when rotating the upper structure with heavy loads
• Hydraulic system derate mode activated, limiting overall machine performance
• Intermittent fault code that appears and disappears, especially on used excavators with worn wiring harnesses

Potential Causes

The most common technical causes for E215 in used PC160LC-7 excavators include:

• Defective swing motor secondary pressure sensor (internal component failure after extended service hours)
• Damaged or corroded wiring harness connections between the sensor and ECM, particularly at the swing bearing area where cables experience constant flexing
• Frayed or pinched wires along the center joint routing path—a known wear point on older PC160LC-7 models
• Contaminated or corroded sensor connector pins due to seal degradation (common in machines operating in wet or coastal environments)
• Failed ECM input circuit (less common, but possible in high-hour machines)
• Low hydraulic oil level or contaminated hydraulic fluid affecting sensor accuracy

How to Troubleshoot and Fix Code E215

Step 1: Visual Inspection Begin by inspecting the swing motor secondary pressure sensor located on the swing motor assembly. Check for physical damage, loose mounting, or hydraulic oil leaks around the sensor body. On used excavators, carefully examine the entire wiring harness from the sensor through the center joint to the ECM, looking for abrasion points, cuts, or areas where the harness contacts metal edges.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor connector and measure resistance across the sensor terminals. Compare readings against Komatsu specifications (typically 200-400 ohms at operating temperature). Check for supply voltage at the connector harness side—should read approximately 5 volts DC. Inspect all connector pins for corrosion, bent terminals, or moisture intrusion, which frequently causes intermittent faults in older machines.

Step 3: Signal Testing and Verification With the sensor reconnected, use Komatsu diagnostic software (KOMTRAX or compatible scan tool) to monitor real-time pressure sensor voltage while operating the swing function. Normal readings should fluctuate between 0.5-4.5 volts depending on pressure conditions. Static voltage outside this range confirms sensor or circuit failure.

Step 4: Component Replacement If diagnostics confirm sensor failure, replace the swing motor secondary pressure sensor with a genuine Komatsu part. For used excavators, simultaneously replace the sensor connector pigtail if any corrosion is present—this prevents recurring faults. After installation, clear fault codes, perform swing function tests under load, and verify code does not return.

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Disclaimer: This guide provides general troubleshooting information for Komatsu PC160LC-7 fault code E215. Hydraulic system repairs involve high-pressure components and require proper training. Always consult your Komatsu service manual and consider professional diagnosis for complex electrical issues or if you lack experience with excavator hydraulic systems.