What is Hitachi ZX210W-3 Fault Code P0603 (10013-2)?

Fault code P0603 (10013-2) on the Hitachi ZX210W-3 wheeled excavator indicates a Keep Alive Memory (KAM) error in the Engine Control Module (ECM). This code signals that the ECM has detected an internal memory malfunction, specifically a failure in the non-volatile memory that stores critical calibration data, learned parameters, and diagnostic information even when power is disconnected.

This is a serious code because the KAM retains essential data like fuel injection timing maps, idle speed adjustments, and emission control parameters. When this memory fails, the ECM cannot maintain proper engine calibration settings, potentially causing the engine to run on default values that reduce performance and fuel efficiency. For used excavators like the ZX210W-3, this often indicates aging ECM components or electrical system degradation.

Common Symptoms

• Check Engine Light or malfunction indicator lamp illuminated on the dashboard
• Engine running in limp mode with reduced power output and limited RPM range
• Rough or unstable idle, especially after cold starts or when the machine has been sitting
• Loss of previously learned adaptive settings, causing the engine to operate as if freshly calibrated
• Difficulty starting or extended cranking times due to lost fuel trim data

Potential Causes

The most common causes of P0603 on used Hitachi ZX210W-3 excavators include:

• ECM internal battery failure – the small backup battery inside the ECM that maintains KAM has depleted (common in machines over 8-10 years old)
• Corroded or loose ECM power supply connectors causing voltage drops during operation
• Wiring harness chafing near the ECM mounting location, particularly where harnesses route along the engine frame rails
• Water intrusion into the ECM housing from damaged seals or improper storage
• Voltage spikes from faulty alternators or poor grounding causing memory corruption
• Failed internal EEPROM chip within the ECM due to age and thermal cycling

How to Troubleshoot and Fix Code P0603 (10013-2)

Step 1: Verify Power Supply Integrity Using a multimeter, check the ECM power supply circuits with the key on. Verify constant battery voltage (12-14V) at pins specified in the Hitachi service manual. Inspect the main ECM connector for corrosion, pushed-back pins, or moisture. On used excavators, pay special attention to connector seal integrity.

Step 2: Check Ground Connections Measure resistance between ECM ground pins and chassis ground – it should be less than 0.5 ohms. Clean all ground points on the engine block and frame where ECM grounds terminate. Corrosion here is extremely common on wheeled excavators exposed to road salt.

Step 3: Inspect Wiring Harness Physically trace the ECM harness from the controller to the engine bay, checking for chafe points, especially where it contacts sharp edges or moving components. Used machines often have harness wear at mounting brackets.

Step 4: ECM Internal Battery Test If external power is confirmed good, the ECM likely has a failed internal backup battery. This requires ECM replacement or professional rebuild. Some specialists can replace the internal battery, but Hitachi typically recommends full ECM replacement for this code.

Step 5: Clear Code and Monitor After repairs, clear the code using Hitachi diagnostic software (Dr.EX) or a compatible scan tool. Monitor for code recurrence over several operating cycles.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Hitachi service manual for your specific machine serial number and consider professional diagnosis for ECM-related issues, as improper repairs can cause additional damage.