Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20))
Maintenance schedule, common problems & OEM parts breakdown
The Komatsu DNP031-3C-E (S/N 42001-UP, D31E-20) is a mid-size crawler dozer in the D31 series, powered by a SAA4D102E-2 turbocharged, air-to-air aftercooled diesel engine producing 56 kW (75 HP) at 2000 rpm. Operating weight is 7,130 kg (15,720 lb). This model succeeded earlier D31 variants and preceded the D31P/PL/PLL-20 generation (S/N 45001-UP). Configurations include standard dozer and power angle tilt (PAT) options.
The D31E-20 introduced Komatsu’s KomStat Hydrostatic Transmission (HST) for variable speed control and dynamic braking, replacing older mechanical drive systems found in previous generations. It matters in the used market as a cost-effective, Tier 4 interim compliant machine for light-to-medium earthmoving. Its compact size allows access to confined jobsites, while the HST system offers smooth operation and reduced maintenance complexity compared to traditional gear-drive dozers.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20)) specifications
Engine
| Engine Model | SAA4D102E-2 |
| Engine Type | Turbocharged and air-to-air aftercooled diesel |
| Net Power | 56 kW (75 HP) @ 2000 rpm |
Weights
| Operating Weight (D31EX) | 7130 kg (15,720 lb) |
Dimensions
| Transport Width | Not documented for this exact serial range — verify with your dealer |
| Transport Height | Not documented for this exact serial range — verify with your dealer |
| Track Gauge | Not documented for this exact serial range — verify with your dealer |
| Ground Clearance | Not documented for this exact serial range — verify with your dealer |
Performance
| Travel Speed | Not documented for this exact serial range — verify with your dealer |
| Drawbar Pull | Not documented for this exact serial range — verify with your dealer |
| Gradeability | Not documented for this exact serial range — verify with your dealer |
| Ground Pressure | Not documented for this exact serial range — verify with your dealer |
Blades
| Blade Type | Komatsu blade geometry (curvature optimized) |
| Blade Capacity | Not documented for this exact serial range — verify with your dealer |
| Blade Width | Not documented for this exact serial range — verify with your dealer |
Service Capacities
| Fuel Tank Capacity | Not documented for this exact serial range — verify with your dealer |
| Hydraulic System Capacity | Not documented for this exact serial range — verify with your dealer |
| Engine Oil Capacity | Not documented for this exact serial range — verify with your dealer |
| Cooling System Capacity | Not documented for this exact serial range — verify with your dealer |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20)) maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the DNP031_3C_E(S/N 42001-UP (D31E-20)) beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize KOWA oil analysis at every 500-hour interval to monitor engine wear metals and hydraulic contamination. Check coolant SCA concentration at 500 hours to prevent liner cavitation. Monitor hydraulic oil particle count and viscosity at 1,000 hours to detect pump or valve wear early. Track fuel dilution and soot levels in engine oil to assess combustion efficiency and filter loading. Use KOMTRAX telematics to correlate fluid condition with load frequency and operating temperatures.
Corrective & Common Repairs
Address hydraulic hose leaks and cracks during daily inspections, particularly around the HST pump and cylinder connections. Replace the hydraulic return filter at 500 hours to protect sensitive valve components. Inspect and clean the radiator and oil cooler fins regularly to prevent overheating in dusty environments. Check track tension and roller/bushing wear to prevent premature undercarriage failure. Replace worn cutting edges and end bits to maintain blade efficiency and reduce drag.
Overhaul & Rebuild Points
Plan for HST pump and motor overhaul based on KOWA analysis results and performance degradation, typically around 10,000-15,000 hours depending on duty cycle. Inspect final drive gears and bearings at 1,000-hour intervals; replace seals and gears as needed. Evaluate engine compression and turbocharger condition at major service intervals. Check structural welds on the blade and push arms for fatigue cracks. Monitor transmission clutch packs for slippage and adjust or replace as necessary.
Seasonal & Environment Servicing
In cold climates, use Komatsu Super Coolant AF-NAC and ensure DEF fluid is protected from freezing. Drain water from the fuel separator daily in humid or wet conditions to prevent microbial growth. In dusty environments, check the air filter restriction indicator frequently and clean or replace the outer element as needed. Inspect seals and boots for damage from UV exposure or chemical contact. Adjust track tension for soft ground to reduce sinkage and improve traction.
DNP031_3C_E(S/N 42001-UP (D31E-20)) common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 195-13-13420 | Filter | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
DNP031_3C_E(S/N 42001-UP (D31E-20)) fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CA115 | Engine crankshaft speed sensor failure | Broken sensor, wiring issue, or connector corrosion | Replace the speed sensor and verify voltage at the pin connector |
| CA441 | Battery voltage too low | Weak battery or charging system failure | Replace the battery or alternator; check the voltage regulator |
| CA442 | Battery voltage too high | Faulty voltage regulator or alternator overcharging | Replace the alternator or battery; check the voltage regulator |
| AA10NX | Air cleaner clogging | Dirty or blocked air filter element | Replace the air filter |
| B@BCNS | Engine coolant overheating | Low coolant level, blocked radiator fins, or fan belt failure | Check radiator fins, fan belt, and coolant level |
| B@HANS | Hydraulic oil overheating | Contaminated hydraulic oil, clogged filter, or cooler fan issue | Change hydraulic filter and oil; check cooler fan |
| CA122 | Intake air pressure high voltage | Malfunction in the intake pressure sensor or actual overpressure condition | Verify the intake pressure sensor and wiring |
| CA123 | Intake air pressure low voltage | Sensor short or airflow restriction | Check for a sensor short or an airflow restriction |
| CA144 | Coolant temperature sensor high error | Coolant temperature sensor feedback voltage too low or short circuit | Replace or test the coolant temperature sensor |
| CA153 | Intake air temperature sensor high error | Intake air temperature sensor feedback voltage is too high | Replace or test the intake air temperature sensor |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
DNP031_3C_E(S/N 42001-UP (D31E-20)) attachments & work tools
Blades
The DNP031-3C-E (S/N 42001-UP) utilizes the D31E-20 configuration, which supports standard straight (S), semi-universal (SU), and angle (A) blade types. VPAT (Power Angle Tilt) blade availability is documented for the D31P-17A variant (S/N 32001-UP), but specific VPAT widths or capacities for the D31E-20 series are not detailed in the provided sources. Typical blade configurations for this class vary by application, with straight blades used for push loading and angle blades for side-hilling.
Rippers
The D31E-20 configuration is listed under the DNP031-3C-E serial range, but specific ripper options (single-shank vs. multi-shank) and their weights are not documented in the provided text. Ripper availability and specifications for this class typically vary by configuration and are not explicitly defined for the D31E-20 in the source material.
Winches
Winch options and towing capacities for the DNP031-3C-E are not specified in the provided sources. The D31E-20 engine configuration is noted for its 56 kW (75 HP) output, but specific winch class or attachment details are absent from the text.
Drawbars/Counterweights
Drawbar and counterweight specifications for the DNP031-3C-E are not detailed in the provided sources. The operating weight for the D31EX variant is listed as 7,130 kg (15,720 lb), but specific counterweight configurations for the D31E-20 are not documented.
Cab/ROPS Guarding
Forestry and waste configuration guarding options for the DNP031-3C-E are not specified in the provided sources. The D31E-20 engine is described as a turbocharged, air-to-air aftercooled diesel, but specific cab or ROPS guarding details for specialized configurations are absent.
Hydraulic Arrangement
The DNP031-3C-E (D31E-20) utilizes a hydraulic pump compatible with part number 705-11-20010. The machine employs Komatsu’s exclusive KomStat Hydrostatic Transmission (HST) for variable speed control and dynamic braking. Specific front/rear tool hydraulic arrangement details are not provided in the source text.
All DNP031_3C_E(S/N 42001-UP (D31E-20)) assemblies by section
Every catalogued assembly group for the Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20)). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Service Kit And Component Parts
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Service Kit And Component Parts : P.T.O. Pump
| 04***15 | Ring, Snap | 1 |
| 70***10 | Seal, Oil | 1 |
| 70***10 | Pump Ass'Y (Sal 8),(See Fig.7663) | 1 |
Work Equipment
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Work Equipment : P.T.O. Case
| 01***30 | Bolt,(For France Noise Suppression) | 4 |
| 01***30 | Bolt,(For Mechanical Governor) | 2 |
| 01***16 | Bolt, Battery To Frame Ground Wire Attaching | 2 |
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Work Equipment : P.T.O. Control Lever
| 01***20 | Bolt,(With Auto Emergency Steering) | 3 |
| 01***30 | Bolt,(For Mechanical Governor) | 1 |
| 01***95 | Bolt,L.H | 4 |
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Work Equipment : P.T.O. Control Valve
| 01***20 | Bolt,(With Auto Emergency Steering) | 4 |
| 01***75 | Bolt,(For Shipping) | 4 |
| 01***06 | Nut,(With Back-Up Alarm) (Op), Nut; Was 01580-10806 | 1 |
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Work Equipment : P.T.O. Oil Piping
| 01***25 | Bolt,Without Revolution Sensor | 4 |
| 01***30 | Bolt,(For Quick Shift) (Mitsubishi) | 4 |
| 01***25 | Washer,Spring?For Additional Rear Lam | 4 |
Komatsu : Dnp031_3c_e(S/N 42001-Up (D31e-20)) : Work Equipment : P.T.O. Shaft And Gear
| 01***20 | Bolt,(Sandy? Dusty Terrain Spec.) | 4 |
| 01***70 | Bolt | 10 |
| 01***25 | Washer,Spring?(Sandy And Dusty Spec.) | 14 |
DNP031_3C_E(S/N 42001-UP (D31E-20)) serial number reference
The Product Identification Number (PIN) plate is riveted to the front frame casting, typically on the operator's left side near the radiator support. Read the prefix as the alphanumeric code preceding the serial number sequence (e.g., DNP031-3C-E) to identify the specific model generation and configuration.
| Prefix | Identifies | Notes |
|---|---|---|
| DNP031-3C-E | D31E-20 | Serial range 42001-UP. Factory spec sheet and parts catalog confirm this prefix identifies the D31E-20 generation bulldozer within the DNP031 family. |
Frequently asked questions
What engine does the DNP031-3C-E (S/N 42001-UP) use?
It uses the Komatsu SAA4D102E-2 turbocharged, air-to-air aftercooled diesel engine, producing 56 kW (75 HP) at 2000 rpm.
What is the operating weight of the DNP031-3C-E?
The operating weight is 7,130 kg (15,720 lb).
What model replaced the DNP031-3C-E?
The DNP031-3C-P (S/N 45001-UP, D31P/PL/PLL-20) and DNP031-3C-D (S/N 45001-UP, D31P-20A) succeeded the D31E-20 series.
What DNP031_3C_E(S/N 42001-UP (D31E-20)) owners discuss
What are the typical powertrain and hydraulic behaviors for the Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20))?
What undercarriage wear patterns and maintenance issues are common for this bulldozer series?
What are the known engine quirks and failure modes for the D31E-20 series?
What are the common electrical and sensor issues reported for this model?
What is the critical item to check when buying a used Komatsu DNP031_3C_E(S/N 42001-UP (D31E-20))?
How should hydraulic weakness when hot be diagnosed?
What safety-critical fix is required for track tension issues?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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