Komatsu PC200LC-8 Fault Code E14 CA2185: Technical Guide

What is Komatsu PC200LC-8 Fault Code E14 CA2185?

Fault Code E14 CA2185 indicates a malfunction in the Swing Motor Secondary Pressure Sensor circuit, specifically detecting an abnormal voltage signal or sensor failure in the hydraulic swing system's pressure monitoring circuit.

This code is generated when the Electronic Control Module (ECM) detects voltage readings outside the expected range (typically 0.5-4.5V) from the secondary pressure sensor monitoring hydraulic pressure in the swing motor circuit. The PC200LC-8's advanced hydraulic management system relies on precise pressure feedback to optimize swing performance and protect the system from over-pressure conditions. When this sensor fails, the machine loses critical data needed for efficient operation and component protection, potentially leading to reduced swing performance or hydraulic system damage if left unaddressed.

Common Symptoms

• Swing function operates erratically or with reduced speed and power during rotation
• Monitor panel displays E14 error code with a hydraulic system warning light illuminated
• Sluggish or jerky swing movements, particularly when starting rotation or under load
• Hydraulic system may enter derate mode, limiting swing speed to protect components
• Increased fuel consumption due to inefficient hydraulic pump compensation

Potential Causes

The most common causes of CA2185 in used PC200LC-8 excavators include:

• Failed swing motor secondary pressure sensor due to internal component degradation (common after 8,000+ hours)
• Corroded or damaged wiring connectors at the sensor harness connection point near the swing motor
• Chafed or pinched sensor harness where wiring passes through the center joint or along the swing bearing area—a known wear point on this model
• Contaminated hydraulic oil causing sensor membrane fouling or failure
• ECM voltage supply issues providing incorrect reference voltage to the sensor
• Water intrusion into sensor connector from damaged seals or improper maintenance

How to Troubleshoot and Fix Code E14 CA2185

Step 1: Visual Inspection Begin by thoroughly inspecting the swing motor secondary pressure sensor located on the swing motor housing. Check for physical damage, oil leaks, or loose mounting. Examine the wiring harness from the sensor through the center joint to the main harness—look specifically for chafing, cuts, or connector corrosion. On used excavators, this harness routing is a common failure point due to repetitive swing motion.

Step 2: Electrical Testing Using a digital multimeter, disconnect the sensor connector and measure resistance across the sensor terminals (typically 250-350 ohms at 20°C). Check for supply voltage at the harness connector with ignition on (should read approximately 5V). Measure signal wire voltage with the sensor connected while operating the swing function—readings should vary smoothly between 0.5-4.5V corresponding to pressure changes.

Step 3: Harness Continuity Check Test continuity from the sensor connector to the ECM connector pins using Komatsu's wiring diagram. Check for shorts to ground or power. Pay special attention to the center joint area where harness flexing occurs.

Step 4: Sensor Replacement and Verification If testing confirms sensor failure, replace with a genuine Komatsu pressure sensor (P/N 7861-93-1650 or equivalent). Before installation on used machines, clean the mounting port thoroughly and apply anti-seize compound. After replacement, clear codes using Komatsu diagnostic software (KOMTRAX Plus) and perform a swing function test under load to verify proper operation.

Critical for Used Equipment: Always inspect hydraulic oil condition and check system pressure specifications before condemning electrical components—contaminated oil can cause repeated sensor failures.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC200LC-8 service manual and consider professional diagnostic assistance for complex hydraulic-electrical issues. Improper repairs may cause safety hazards or further equipment damage.