What is Komatsu PC200-10 Fault Code CA1695?

Fault Code CA1695 indicates a malfunction in the Engine Control Module (ECM) communication circuit with the hydraulic pump control system. Specifically, this code triggers when the main controller detects an abnormal signal or loss of communication between the ECM and the proportional pressure control solenoid that regulates hydraulic pump output on the Komatsu PC200-10.

This code is critical because the PC200-10 uses an integrated CLSS (Closed-Center Load Sensing System) where engine power and hydraulic demand must communicate constantly. When communication fails, the machine may enter a protective derate mode to prevent damage, significantly limiting productivity and potentially causing unsafe operating conditions on the jobsite.

Common Symptoms

When CA1695 is active on your PC200-10, operators typically experience:

• Warning lamp illuminated on the monitor panel with error message displayed
• Reduced hydraulic power across all functions (boom, arm, bucket, and swing operations feel sluggish)
• Engine derate limiting maximum RPM to approximately 1,500-1,800 RPM
• Erratic hydraulic response where pump flow doesn't match joystick input
• Intermittent loss of multi-function capability during combined operations

Potential Causes

The most common technical causes for CA1695 on used PC200-10 excavators include:

• Damaged wiring harness between ECM and hydraulic pump control valve (common rub point near engine mount)
• Corroded or loose connector pins at the pump solenoid (C-connector behind left-side service door)
• Failed proportional solenoid valve due to contaminated hydraulic oil or electrical burnout
• ECM internal fault or software corruption requiring reprogramming
• Voltage supply issues from main power harness (low voltage under 22V can trigger false codes)
• Hydraulic oil contamination affecting solenoid magnetic coil resistance

How to Troubleshoot and Fix Code CA1695

Step 1: Initial Inspection Using Komatsu KOMTRAX or an aftermarket diagnostic tool, capture freeze-frame data showing when the fault occurred. Check battery voltage—it must be above 24V during cranking. Inspect the main harness routing from ECM (located under operator seat) to the hydraulic pump solenoid valve.

Step 2: Electrical Testing Disconnect the C-connector at the proportional control solenoid. Using a digital multimeter, measure resistance across solenoid terminals—specification is typically 8-12 ohms at 20°C. Check for voltage supply at connector (should read 24V with key on). Inspect connector pins for corrosion, bent pins, or moisture intrusion—extremely common on used machines operating in wet conditions.

Step 3: Component Verification If electrical values are correct, perform a solenoid activation test using diagnostic software to command the valve open/closed while monitoring current draw (should be 1.8-2.2A). On used excavators, remove the solenoid and inspect for metal contamination or varnish buildup. Replace hydraulic oil filters and check oil cleanliness—contamination codes often appear together with communication faults.

Step 4: Advanced Diagnostics If all components test normally, the issue may be ECM-related. Check for available software updates from Komatsu—several TSBs address communication protocols. Verify CAN bus termination resistance (should read 60 ohms across CAN-H and CAN-L with all modules connected).

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Komatsu PC200-10 service manual and consider professional diagnostic assistance for complex electrical issues. Improper repairs may void warranties or create safety hazards.