What is Hitachi ZX210LCH-5G Fault Code 13304-2?

Fault Code 13304-2 indicates a malfunction in the aftertreatment diesel particulate filter (DPF) differential pressure sensor circuit, specifically detecting an abnormal voltage signal or intermittent connection. This code triggers when the Engine Control Module (ECM) receives voltage readings outside the expected range from the DPF differential pressure sensor, which monitors exhaust backpressure across the diesel particulate filter.

This sensor is critical for the ZX210LCH-5G's emissions control system because it tells the ECM when regeneration cycles are needed to burn off accumulated soot. When this circuit fails, the machine cannot properly manage DPF regeneration, potentially leading to filter clogging, reduced engine performance, and compliance issues with emission standards. In used excavators, this fault often stems from sensor degradation or wiring harness damage rather than actual DPF problems.

Common Symptoms

• Engine derate mode activating, limiting maximum RPM and hydraulic performance
• Exhaust system warning light illuminated on the instrument cluster
• Frequent or failed automatic regeneration attempts with excessive exhaust temperatures
• Black smoke from exhaust during operation due to incomplete combustion
• Reduced fuel efficiency and noticeable loss of digging force or cycle times

Potential Causes

The most common technical causes for Code 13304-2 on used ZX210LCH-5G excavators include:

• Damaged or corroded wiring harness connections at the DPF differential pressure sensor (common rub point near the turbocharger heat shield)
• Failed differential pressure sensor due to carbon buildup or internal electrical failure
• Voltage supply issues from the ECM, including poor ground connections at the chassis mounting point
• Contaminated sensor ports blocked by soot or ash preventing accurate pressure reading
• ECM software corruption or outdated calibration files (less common but possible in older machines)
• Physical damage to sensor tubing or hoses connecting to the DPF assembly

How to Troubleshoot and Fix Code 13304-2

Step 1: Connect Hitachi diagnostic software (Dr.EX) or compatible scanner to retrieve freeze frame data and verify the fault is current, not historic.

Step 2: Perform a visual inspection of the DPF differential pressure sensor located on the exhaust system. Check for damaged wiring, melted insulation near hot components, and corroded connectors. Clean all connector pins with electrical contact cleaner.

Step 3: Using a digital multimeter, test sensor voltage with ignition on/engine off. You should read approximately 5 volts on the supply wire. Check resistance between sensor ground and chassis ground—readings above 1 ohm indicate poor grounding.

Step 4: Inspect pressure sensing hoses for cracks, blockages, or carbon deposits. Remove and clean hoses with compressed air. On used excavators, these hoses often become brittle and crack.

Step 5: If wiring and connections test properly, replace the differential pressure sensor with a genuine Hitachi part. Clear codes and perform a forced regeneration cycle to verify repair.

Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual and consider professional diagnostic assistance for complex electrical issues or if you lack proper diagnostic equipment.