What is Hitachi ZX890H-5A Fault Code 13303-2?

Fault Code 13303-2 on the Hitachi ZX890H-5A indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a data link error between the ECM and the machine's main controller. This code triggers when the Controller Area Network (CAN) bus experiences intermittent or complete signal loss, preventing critical engine performance data from reaching the hydraulic control system.

This fault is particularly critical on the ZX890H-5A because this ultra-class excavator relies on integrated electronic control systems to coordinate engine output with hydraulic demand. When communication fails, the machine cannot optimize fuel delivery, throttle response, or implement proper engine protection protocols. For used excavators, this code often indicates aging wiring harnesses or corroded connector pins rather than actual ECM failure.

Common Symptoms

• Engine derate mode activating unexpectedly, limiting machine to 70-80% power output
• Intermittent check engine light or ECM warning on the monitor display
• Erratic throttle response or inability to achieve full RPM under load
• Hydraulic system performance degradation due to improper engine-pump coordination
• Fault code appearing and disappearing during machine operation, especially when vibrating or moving

Potential Causes

The most common causes for Code 13303-2 on used ZX890H-5A excavators include:

• CAN bus wiring harness damage at known rub points near the engine mount brackets and along the boom base
• Corroded or loose connections at the 120-pin ECM connector (C1) or main controller harness connector
• Water intrusion into connector housings, particularly the ECM bulkhead connector behind the battery box
• Failed termination resistors on the CAN bus network (should measure 60 ohms across CAN-H and CAN-L)
• Deteriorated connector seals allowing moisture into the J1939 data link circuit
• Voltage irregularities from aging batteries or faulty alternator affecting ECM power supply

How to Troubleshoot and Fix Code 13303-2

Step 1: Visual Inspection Begin by inspecting all wiring harnesses between the ECM (located behind the right-side service door) and the main controller. On used machines, check for harness chafing where cables contact the engine block, frame rails, and hydraulic lines. Examine all connector boots for cracks or moisture intrusion.

Step 2: Connector and Resistance Testing Disconnect the ECM connector C1 and inspect pins 23 (CAN-H) and 24 (CAN-L) for corrosion or bent contacts. Using a digital multimeter, measure resistance between CAN-H and CAN-L terminals with all controllers disconnected—you should read approximately 60 ohms if termination resistors are functioning. Clean all connector pins with electrical contact cleaner and apply dielectric grease before reconnection.

Step 3: CAN Bus Signal Testing With the key on (engine off), use a multimeter set to DC voltage. Measure voltage on CAN-H (should read 2.5-3.5V) and CAN-L (should read 1.5-2.5V) relative to chassis ground. Fluctuating readings indicate intermittent connections. If available, connect Hitachi Dr.EX diagnostic software to monitor real-time CAN bus activity and identify specific communication dropouts.

Step 4: Harness Repair and Component Replacement For used excavators, repair damaged harness sections using OEM-spec wiring and heat-shrink connectors rather than replacing entire harnesses. Replace any connectors showing green corrosion. If all wiring tests pass, the ECM or main controller may require replacement, though this is rare compared to harness issues on high-hour machines.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number and seek assistance from certified Hitachi technicians for complex electrical diagnostics or ECM programming procedures.