What is Hitachi ZX870-5A Fault Code 13311-3?

Fault Code 13311-3 on the Hitachi ZX870-5A excavator indicates a malfunction in the Engine Control Module (ECM) communication circuit, specifically a CAN (Controller Area Network) bus communication error between the engine ECM and the machine's main controller. This code signals that data transmission between critical control systems has been interrupted or degraded, preventing proper coordination between engine management and hydraulic functions.

The CAN bus system serves as the central nervous system for modern excavators, allowing the engine ECM, hydraulic controller, and monitor display to share real-time operational data. On the ZX870-5A, this communication network is essential for optimizing fuel injection timing, managing hydraulic flow rates, and coordinating engine speed with load demands. When this circuit fails, the machine cannot properly regulate performance parameters, potentially leading to inefficient operation or protective shutdowns.

Common Symptoms

• Warning light illumination on the instrument cluster, often accompanied by a "Check Engine" or "System Error" message on the digital display
• Reduced engine power or activation of derate mode, limiting machine performance to protect components
• Erratic hydraulic response, including sluggish boom or bucket movements due to loss of coordinated control signals
• Intermittent engine stalling or rough idling, particularly during cold starts or when transitioning between work modes
• Inability to access diagnostic information through the monitor panel, as communication pathways are compromised

Potential Causes

The most common technical failures triggering Code 13311-3 on used ZX870-5A excavators include:

• Damaged CAN bus wiring harness, particularly at known rub points near the engine firewall and along the right-side chassis rail where cables flex during boom operation
• Corroded or loose connector pins at the ECM or main controller junction boxes, especially the 38-pin ECM connector which is prone to moisture intrusion
• Failed termination resistors within the CAN network (typically 120-ohm resistors at network endpoints)
• ECM internal failure or corrupted software, more common in machines exceeding 8,000 operating hours
• Voltage supply issues from the main power distribution module affecting ECM operation (nominal 24V system)
• Aftermarket component interference, such as improperly installed telematics devices tapping into the CAN network

How to Troubleshoot and Fix Code 13311-3

Step 1: Visual Inspection of Harness and Connectors Begin by inspecting the CAN bus wiring harness from the engine ECM to the main controller cabinet. On used excavators, pay particular attention to areas where the harness passes through bulkheads or contacts metal edges. Look for abraded insulation, pinched wires, or signs of rodent damage. Disconnect and inspect all related connectors, cleaning contacts with electrical contact cleaner and checking for bent pins or green corrosion deposits.

Step 2: Verify CAN Bus Integrity with Multimeter Using a digital multimeter, measure resistance between the CAN-High and CAN-Low terminals at the ECM connector (typically pins 24 and 25 on Hitachi systems). You should read approximately 60 ohms with the key off, indicating proper termination resistors are in place. Next, check for continuity along each CAN wire from ECM to controller, ensuring readings below 2 ohms. Any open circuits or resistance above 5 ohms indicates a break in the wiring.

Step 3: Test Voltage Supply and Ground Circuits With the key in the "ON" position (engine off), verify the ECM receives proper supply voltage (23.5-25V DC) at the power input pin and that ground circuits show less than 0.1V drop to chassis ground. Poor grounding is a frequent issue in high-hour machines due to corrosion at grounding points near the battery box.

Step 4: Advanced Diagnostics with Hitachi Dr.EX Software Connect Hitachi Dr.EX diagnostic software (or compatible third-party tools like Jaltest) to the machine's diagnostic port. Monitor live CAN bus traffic and check for message error rates. Error rates above 5% indicate network instability. The software can also identify which specific controller is failing to respond, narrowing down whether the issue originates from the engine ECM or machine controller side.

Step 5: Component Replacement and Verification If diagnostics point to a failed ECM, ensure replacement units are programmed with the correct software version for the ZX870-5A model year. After repairs, clear fault codes and perform a complete operational test cycling through all machine functions while monitoring for code recurrence.

Disclaimer: This guide provides general troubleshooting information for experienced technicians. Always consult the official Hitachi service manual for your specific machine serial number and software version. Complex electrical diagnostics should be performed by certified technicians with proper diagnostic equipment. Improper repairs to CAN bus systems can result in multiple controller failures and significant repair costs.