Whether you're on a job site staring at a flashing warning light or back in the shop trying to figure out why your machine won't perform, understanding your Komatsu PC200-8's monitor error codes can save you hours — and thousands of dollars.
This guide covers the most common error codes on the PC200-8 (and related models like the PC210-8, PC220-8, and PC240-8), what each one means, and practical steps you can take to diagnose and fix the problem.
How the Komatsu PC200-8 Monitor System Works
The PC200-8 uses a digital instrument cluster — the monitor panel — to display machine operating data in real time. When the onboard diagnostic system detects a fault, it triggers one of three responses:
- Caution lamp (yellow): something needs attention soon
- Action lamp (red): stop the machine and investigate immediately
- Numeric error code: displayed on the monitor screen, typically in the format "E-XX" or a numeric string
Codes are stored in the machine's ECU and can be read directly from the monitor screen or via a diagnostic tool connected to the service port.
Most Common Komatsu PC200-8 Monitor Error Codes
E01 — Coolant Temperature Overheat
What it means: Engine coolant temperature has exceeded the safe operating threshold (typically above 105°C).
What to check:
- Coolant level in the reservoir and radiator
- Radiator fins for mud, debris, or damage
- Water pump condition and belt tension
- Thermostat function
- Coolant temperature sensor (part number: 7861-93-3320)
Quick fix: Shut down immediately, let the machine cool. Check coolant level first. If it's low and the radiator shows no visible damage, top up and monitor. Persistent overheating usually points to a failing water pump or clogged radiator.
E02 — Engine Oil Pressure Low
What it means: Oil pressure has dropped below the minimum operating level. This is a critical fault — continued operation risks severe engine damage.
What to check:
- Engine oil level (dipstick)
- Oil filter condition (replace if overdue)
- Oil pressure sensor — a faulty sensor can cause false readings
- Oil pump wear (PC200-8 uses a gear-type oil pump)
Part to inspect: Engine oil pressure sensor, part number 7861-93-1650. These sensors are a common culprit for false E02 codes on high-hour machines.
E03 — Battery Charge Fault / Alternator Warning
What it means: The alternator is not charging the battery properly. You may notice the battery warning lamp alongside this code.
What to check:
- Battery terminal connections (corrosion or looseness)
- Alternator output voltage (should be 27–29V when running)
- Alternator belt tension and condition
- Alternator itself — internal regulator failure is common after 3,000–5,000 hours
How to test: With the engine running, use a multimeter across the battery terminals. A reading below 26V suggests the alternator is not charging. A reading at or above 28V with the E03 code active suggests a faulty sensor or wiring issue rather than the alternator itself.
E10 — Fuel System Fault
What it means: A fault has been detected in the fuel injection system. On the PC200-8, this often relates to the common rail fuel injection system (Komatsu uses Denso-supplied injectors on the 4D107 engine).
What to check:
- Fuel filter condition (replace every 500 hours)
- Fuel injector rail pressure
- Individual injector performance (requires diagnostic tool)
- Fuel lift pump function
Common injector part numbers for PC200-8 (4D107 engine):
- 6754-11-3010 / 6754-11-3011 — standard rail injector
A single misfiring injector is often the cause of E10 alongside rough idle, black smoke, or power loss.
Related product: Fuel Injector for Komatsu
E15 — Throttle / Governor Motor Fault
What it means: The electronic throttle control (governor motor) is not responding correctly. The engine may idle at a fixed RPM and not respond to throttle lever input.
What to check:
- Governor motor wiring harness for damage or loose connectors
- Governor motor mechanical operation (manually move the linkage — it should move smoothly)
- Controller output signal to the governor motor
Part number: Governor throttle motor 7834-40-3000 (PC200-8 compatible). This is a commonly replaced part on PC-8 series machines.
E20 — Hydraulic Oil Temperature Warning
What it means: Hydraulic oil temperature is too high. Often triggered during extended heavy-duty work in hot climates.
What to check:
- Hydraulic oil level
- Oil cooler fins for blockage
- Hydraulic fan motor operation
- Return filter condition
Note: If you see E20 during light work or on a cool day, suspect a faulty hydraulic oil temperature sensor before assuming a mechanical problem.
E30 — Pump Control Fault
What it means: The hydraulic pump controller is not receiving correct signals or the pump is not responding to commands. This can cause sluggish or unresponsive hydraulic functions.
What to check:
- Main pump solenoid valve function
- Pump controller wiring
- Pump regulator and servo piston
- Main control valve condition
This code often accompanies a noticeable drop in digging or lifting force.
Related product: Hydraulic Pump Assembly for Komatsu
E36 — Pilot Pressure Fault
What it means: Pilot pressure in the hydraulic control circuit is below spec. Without adequate pilot pressure, the joysticks may feel heavy or unresponsive.
What to check:
- Pilot relief valve pressure (spec: approximately 3.9 MPa / 565 psi)
- Pilot filter element
- Pilot pump condition
EA (Action Code) — Immediate Shutdown Required
If the monitor displays a red action lamp alongside any code, the machine must be stopped. Action codes typically accompany:
- Extreme coolant temperature
- Critically low oil pressure
- Severe hydraulic fault
Do not attempt to continue working. Overriding an action lamp condition almost always results in expensive component failure.
How to Clear Error Codes on a Komatsu PC200-8
Method 1 — From the monitor (soft reset):
- Turn the key to ON (engine off)
- Hold the wiper switch and press the shift key simultaneously
- Navigate to the maintenance screen
- Select "Fault Code History" and clear
Note: Clearing codes without fixing the underlying fault will cause them to reappear.
Method 2 — Using a diagnostic tool: The PC200-8 uses a Komatsu KOMTRAX or S·A·A·S diagnostic port (7-pin). Third-party tools compatible with Komatsu's EMMS (Electronic Monitoring and Management System) can read live data and clear fault codes.
Related product: Excavator Diagnostic Tools
When to Replace vs. Repair
| Symptom | Likely Cause | Recommended Action |
|---|---|---|
| Code clears and stays gone | Temporary sensor glitch | Monitor closely |
| Code returns within hours | Sensor or wiring fault | Replace sensor first |
| Code returns with performance loss | Mechanical component failure | Full diagnosis required |
| Multiple codes active simultaneously | ECU or wiring harness issue | Check controller and harness |
Related Models
Most of the error codes and part numbers in this guide also apply to:
- Komatsu PC210-8 / PC210LC-8
- Komatsu PC220-8
- Komatsu PC240-8
- Komatsu PC270-8
These models share the same SAA4D107E-1 or SAA6D107E-1 engine platform and similar monitor systems.
Need the Part? SINOCMP Has You Covered
Sinocmp stocks aftermarket replacement parts for all major Komatsu PC-8 series machines, including monitors, controllers, fuel injectors, governor motors, alternators, and hydraulic components — all shipped worldwide.
- 🔍 Search by part number or machine model
- ✅ Quality-inspected before dispatch
- 🚀 DHL / FedEx / UPS worldwide shipping
- 🛡️ 12-month warranty on most parts
Shop Komatsu Parts at Sinocmp →
Have a fault code not listed here? Contact our technical team at service@sinocmp.com — we're happy to help identify the right part for your machine.
