Actuator Power Supply 1 - Voltage Low

Komatsu Heavy Equipment Warning Electrical

Model: Komatsu PC290 Excavator | Code: CA451

Applicable Systems
PC200 Excavator

Symptoms

Actuator power supply voltage below minimum; solenoid valves may not operate correctly; reduced hydraulic control.

Possible Causes

  • Actuator power supply relay faulty
  • Power supply fuse blown
  • Wiring from relay to actuator damaged

Troubleshooting Steps

  1. Step 1: Check actuator power supply fuse (30A)
    Fuse intact
  2. Step 2: Check relay operation
    Relay energizes, contacts close
  3. Step 3: Measure voltage at actuator power terminal
    Voltage >= 11.5V with engine running
  4. Step 4: Inspect wiring for damage
    Wiring intact
  5. Step 5: Replace relay or repair wiring
    Voltage stable at actuator

How to Reset

Clear via service monitor after power supply repair.

Common Replacement Parts

  • Actuator Power Relay P/N: 600-66-11110
  • 30A Fuse

Frequently Asked Questions

  • Q: What are actuator solenoids on excavator?

    Electromagnetic valves controlling hydraulic functions: boom, arm, bucket, swing, travel, and auxiliary. Each solenoid directs hydraulic flow to specific circuit.

Related Komatsu Fault Codes

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Source: truckmanualshub.com Komatsu PDF

Category: Heavy Equipment