What is Hitachi ZX210H-5G-HCMC Fault Code 14107-2?

Fault Code 14107-2 indicates a malfunction in the DEF (Diesel Exhaust Fluid) pump circuit, specifically detecting an abnormal current or voltage signal from the pump control system. This code is part of Hitachi's emissions control diagnostics for Tier 4 Final compliant engines equipped with Selective Catalytic Reduction (SCR) technology.

The DEF pump is responsible for injecting precise amounts of urea solution into the exhaust stream to reduce NOx emissions. When the Engine Control Module (ECM) detects irregular electrical signals from the pump—whether too high, too low, or intermittent—it triggers code 14107-2. This fault is critical because continued operation without proper DEF injection can result in engine derate (reduced power output) or complete shutdown to maintain EPA compliance. On used excavators like the ZX210H-5G-HCMC, this code often appears due to age-related electrical degradation rather than mechanical pump failure.

Common Symptoms

• Amber or red warning light illuminated on the instrument panel, specifically the SCR/emissions system indicator
• Engine power derate after a predetermined grace period (typically 50-100 operating hours), limiting machine to 50-75% power
• Intermittent loss of DEF injection, visible through diagnostic software showing zero flow rates during active regeneration
• Error messages on the monitor display referencing "Exhaust System" or "DEF System Fault"
• Increased fuel consumption as the ECM attempts to compensate for incomplete emissions reduction

Potential Causes

On used ZX210H-5G-HCMC excavators, this code commonly stems from:

• Corroded or damaged wiring harness at the DEF pump connector, particularly where the harness routes near the frame rail (known rub point on this model)
• Failed DEF pump motor due to crystallized urea contamination from prolonged storage or poor-quality DEF fluid
• Faulty pump relay or blown fuse in the DEF system power circuit
• Degraded ground connection at the pump mounting bracket causing voltage fluctuations
• ECM internal fault (rare) where the pump driver circuit has failed
• Contaminated DEF tank causing pump overload and excessive current draw

How to Troubleshoot and Fix Code 14107-2

Step 1: Visual Inspection
Inspect the DEF pump wiring harness from the pump to the main chassis harness connector. On used machines, check for chafing where the harness crosses the frame near the fuel tank mounting bracket—this is a documented wear point. Look for corroded pins, moisture intrusion, or damaged insulation. Clean all connector terminals with electrical contact cleaner.

Step 2: Electrical Testing
Using a digital multimeter, disconnect the pump connector and measure resistance across the pump motor terminals (should read 2-5 ohms typically). Check for 12V supply voltage at the harness connector with ignition on. Verify ground continuity from the pump housing to battery negative (should be less than 0.5 ohms).

Step 3: Pump Current Draw Test
Reconnect the pump and use a clamp ammeter to measure operating current during a commanded pump cycle via Dr.EX diagnostic software (Hitachi's proprietary tool). Normal draw is 3-8 amps; readings above 12 amps indicate a seized or contaminated pump.

Step 4: Component Replacement
If electrical tests pass but the code persists, replace the DEF pump assembly. For used excavators, always drain and inspect DEF fluid quality—crystallized or discolored fluid indicates contamination requiring full system flush. Replace the DEF filter simultaneously.

Step 5: Clear Codes and Verify
After repairs, clear fault codes using diagnostic software and perform a pump prime cycle. Monitor live data to confirm proper current draw (typically 4-6 amps) and flow rate response.

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Disclaimer: This guide provides general troubleshooting information. Always consult the Hitachi ZX210H-5G-HCMC service manual and consider professional diagnosis for complex electrical issues. Improper repairs to emissions systems may violate environmental regulations.