If your Komatsu excavator is displaying an error code on the monitor panel, it’s crucial to understand what it means before attempting repairs. Whether you operate a PC200-6, PC200-7, or the electronically controlled PC200-8 series, these codes are the first step toward accurate diagnosis.
At Engine Replacement Parts, we specialize in providing high-quality replacement components—from engine controllers and sensors to IMV valves and injectors—to get your machine back to peak performance. Use this guide to identify the fault, then let us supply the parts you need.
Understanding Komatsu Fault Code Systems
- User Codes: Displayed automatically on the monitor panel to alert the operator.
- Service Codes: Require a switch operation to access deeper diagnostic information.
- Model Break: The -6 and -7 series use mechanical (pre-common rail) engines, while the -8 series features electronic common rail engines with a distinct code set.
Part 1: PC200-6 / PC300-6 / PC400-6 / PC200-7 Series Codes
These models utilize the HYPER system. Below are the most frequently encountered codes.
User Codes (Auto Display)
| Code | System |
|---|---|
| E01 | HYPER System – Auto Mode |
| E02 | PC-EPC System |
| E03 | Swing Parking Brake System |
| E04 + CALL | HYPER System – Joystick Neutral System |
| E05 | Governor Motor System |
| E06 + CALL | HYPER System – EPC Solenoid Drive System |
| E09 | HYPER-GX System Shutdown |
| CALL | HYPER Joystick / EPC Solenoid Drive System |
Service Codes (Switch-Operated)
| Code | Fault Description | Common Component Issue |
|---|---|---|
| E101 | Abnormal fault history record | Controller memory |
| E103 | Buzzer output short circuit | Wiring harness |
| E104 | Air cleaner clogged | Air filter replacement |
| E108 | Coolant temperature ≥105°C | Cooling system |
| E202 | LS select solenoid circuit short | LS-EPC solenoid |
| E203 / E213 | Swing parking brake solenoid short / open | Brake solenoid |
| E204 / E214 | Pump merging/dividing solenoid short / open | Solenoid valve |
| E205 / E215 | 2-stage relief solenoid short / open | Relief solenoid |
| E206 / E216 | Travel speed solenoid short / open | Travel speed solenoid |
| E222 / E223 | LS-EPC solenoid short / open | LS-EPC valve |
| E224 / E225 | Front / Rear pump pressure sensor abnormal | Pressure sensor |
| E227 | Engine speed sensor abnormal | Speed sensor |
| E306 | Feedback potentiometer abnormal | Governor potentiometer |
| E316 | Governor motor misadjustment | Governor motor |
| E317 / E318 | Governor motor open / short | Governor motor |
Note: These codes often indicate solenoid or sensor failure. Replacing the faulty component—such as the governor motor, pressure sensors, or EPC solenoids—typically resolves the issue.
Part 2: PC200-8 Series Codes (Common Rail Engine)
The PC200-8 and PC200LC-8 models use a common rail fuel system with advanced electronics. Codes are divided into User Codes, Engine Controller Codes (CA), and Hydraulic/Pump Codes (D).
User Codes
| Code | System |
|---|---|
| E02 | PC-EPC System |
| E03 | Swing Parking Brake System |
| E10 | Engine controller power supply failure (engine stops) |
| E11 | Engine control system failure (power reduced) |
| E14 | Feedback system abnormality |
| E15 | Engine sensor fault (water temp, fuel pressure, oil pressure) |
| EOE | Network communication failure |
Engine Control Codes (CA Series)
Critical for diagnosing engine performance issues, stalling, or no-start conditions.
| Code | Fault | Typical Root Cause / Part |
|---|---|---|
| CA111 | ECM internal fault | Engine control module |
| CA115 | Engine speed sensor & backup sensor failure | Crankshaft position sensor |
| CA122 / CA123 | Intake pressure sensor high / low | Boost pressure sensor |
| CA131 / CA132 | Throttle dial sensor high / low | Throttle position sensor |
| CA144 / CA145 | Coolant temperature sensor high / low | ECT sensor |
| CA153 / CA154 | Intake temperature sensor high / low | IAT sensor |
| CA187 / CA227 | Sensor power supply voltage low / high | 5V reference circuit |
| CA221 / CA222 | Atmospheric pressure sensor high / low | Barometric sensor |
| CA234 | Engine overspeed | Speed sensor / ECM |
| CA238 | Ne speed sensor power supply voltage | Speed sensor circuit |
| CA271 / CA272 | IMV / PCV1 short / open | Inlet metering valve (IMV) |
| CA322 – CA332 | Injector #1 – #6 open / short | Fuel injectors |
| CA342 | Incorrect calibration code | ECM calibration |
| CA351 | Injection drive circuit failure | Injector driver / ECM |
| CA428 / CA429 | Fuel water separator sensor high / low | Water-in-fuel sensor |
| CA441 / CA442 | Battery voltage low / high | Alternator / battery |
| CA449 / CA451 / CA452 | Common rail pressure high / sensor high / low | Rail pressure sensor / IMV |
| CA488 | Intake air temperature high (torque reduced) | Charge air cooler |
| CA553 / CA559 | Common rail pressure high / low | IMV / fuel supply |
| CA689 | Engine speed sensor failure | Speed sensor |
| CA2185 / CA2186 | Throttle dial power supply high / low | Throttle sensor circuit |
| CA2249 | Common rail pressure low | Fuel supply / IMV |
| CA2311 | IMV solenoid coil failure | Inlet metering valve |
IMV Valve (CA271, CA272, CA2311) is one of the most common failure points on PC200-8 models. A faulty IMV can cause stalling, surging, or hard starting. We carry OEM-grade replacements ready to ship.
Hydraulic & Pump System Codes (D Series)
| Code | Fault | Component |
|---|---|---|
| DHPAMA / DHPBMA | Front / Rear pump pressure sensor abnormal | Pump pressure sensor |
| DHS3MA – DHSbMA | PPC pressure sensor faults | Joystick / pedal sensors |
| DHX1MA | Overload sensor abnormality | Overload sensor |
| DXA8KA / DXA8KB | Front pump PC-EPC solenoid open / short | PC-EPC valve |
| DXA9KA / DXA9KB | Rear pump PC-EPC solenoid open / short | PC-EPC valve |
| DXE0KA / DXE0KB | LS-EPC solenoid open / short | LS-EPC valve |
| DXE5KA / DXE5KB | Main pump merging/dividing solenoid open / short | Merging solenoid |
| DW43KA / DW43KB | Travel speed solenoid open / short | Travel speed solenoid |
| DW45KA / DW45KB | Swing holding solenoid open / short | Swing brake solenoid |
| DW91KA / DW91KB | Travel merging solenoid open / short | Travel control |
| DWK0KA / DWK0KB | 2-stage relief solenoid open / short | Relief solenoid |
| DY20KA / DY20MA | Wiper operation / parking abnormal | Wiper motor |
LC Series Additional Codes (PC200LC-8, PC210LC-8, PC240LC-8)
| Code | Description |
|---|---|
| 989L00 / 989M00 / 989N00 | Engine controller lock warning |
| AA10NX | Air cleaner clogged |
| B@BAZG | Low engine oil pressure |
| B@BCNS | Engine coolant overheating |
| B@HANS | Hydraulic oil overheating |
| DA25KP | 5V sensor power supply abnormal |
| DA2RMC / DAFRMC | CAN bus break (pump or monitor side) |
Common Failure Patterns & Recommended Parts
| Symptoms | Likely Code | Suggested Replacement Part |
|---|---|---|
| Engine stalls, surges, or won’t start | CA271, CA272, CA2311 | IMV (Inlet Metering Valve) |
| Poor acceleration, low power | E11, CA449, CA2249 | IMV, Fuel Supply Pump, or Rail Pressure Sensor |
| No communication, dead display | EOE, DA2RMC | CAN Bus Harness, ECM, or Monitor |
| Machine moves slowly or lacks power | E02, DXA8/DXA9, DXE0 | PC-EPC or LS-EPC Solenoid |
| Engine speed unstable | E05, E316, E317, E318 | Governor Motor or Speed Sensor |
| Injector circuit codes | CA322–CA332 | Fuel Injector(s) |
Pro Tips for Troubleshooting
- Always verify the series: Do not use PC200-6 codes on a PC200-8. They are not interchangeable.
- Check battery voltage first: Many CA codes (CA441, CA442, CA187) are caused by low or unstable electrical power.
- Inspect wiring harnesses: Corroded or chafed wires often cause solenoid and sensor codes before the component itself fails.
- Use genuine or OEM-grade replacements: Aftermarket sensors and solenoids often lead to recurring codes or improper machine performance.
Need Help Diagnosing or Finding a Part?
At Engine Replacement Parts, we supply everything from complete engines and ECMs to IMV valves, injectors, sensors, and solenoids for Komatsu excavators. If you have a fault code and are unsure which part to order, contact our team with your machine model and serial number—we’ll help you find the right replacement.
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Don’t let fault codes slow down your job. Identify the code, find the part, and get back to work with Engine Replacement Parts.