What is Sany SY245/265H Fault Code 132?

Fault Code 132 on the Sany SY245/265H excavator indicates a malfunction in the Engine Coolant Temperature (ECT) Sensor Circuit, specifically detecting an abnormally high voltage signal or open circuit condition. This diagnostic trouble code (DTC) is generated by the Mitsubishi Heavy Industries engine's Electronic Control Module (ECM) when it receives sensor readings outside the normal operating parameters (typically above 4.5 volts).

The ECT sensor plays a critical role in the Mitsubishi engine management system by monitoring coolant temperature and sending voltage signals to the ECM. This data directly influences fuel injection timing, idle speed control, and engine protection protocols. When Code 132 triggers, the ECM enters a default mode using predetermined temperature values, which can compromise engine efficiency and potentially cause long-term damage if left unaddressed.

Common Symptoms

• Check Engine Light or malfunction indicator lamp illuminated on the instrument panel
• Engine running excessively rich or lean, resulting in black smoke or poor fuel economy
• Difficulty starting, especially in cold weather conditions, due to improper fuel/air mixture calculations
• Engine fan running continuously at high speed regardless of actual operating temperature
• Reduced engine power or derate mode activation to prevent potential overheating damage

Potential Causes

The most frequent causes of Code 132 on used Sany SY245/265H excavators include:

• ECT sensor failure due to internal element degradation or moisture intrusion (common after 5,000+ operating hours)
• Wiring harness damage at known rub points near the engine mount brackets and valve cover area
• Corroded or loose connector pins at the sensor plug, particularly on machines operated in wet or marine environments
• Open circuit caused by broken wires within the engine harness insulation, often invisible from external inspection
• Faulty ECM ground connections creating voltage reference issues (less common but critical to verify)
• Previous repair attempts using non-OEM sensors with incorrect resistance specifications

How to Troubleshoot and Fix Code 132

Step 1: Visual Inspection Begin by locating the ECT sensor on the engine block (typically near the thermostat housing). Inspect the sensor connector for corrosion, bent pins, or moisture. On used excavators, carefully examine the wiring harness routing for signs of abrasion against engine components, especially where the harness passes near vibrating parts or hot exhaust manifolds.

Step 2: Electrical Testing Disconnect the ECT sensor connector and use a digital multimeter to measure sensor resistance. At room temperature (20°C/68°F), resistance should typically read 2,000-3,000 ohms (consult Mitsubishi specifications). Test harness continuity from the ECM connector to the sensor plug, checking for resistance below 5 ohms. Measure voltage supply from the ECM with ignition on—should read approximately 5 volts.

Step 3: Component Replacement and Verification If testing confirms sensor failure, replace with OEM-equivalent parts designed for Mitsubishi Heavy Industries engines. For used machines, always apply dielectric grease to connector pins to prevent future corrosion. Clear fault codes using diagnostic software (Mitsubishi MUT-III or compatible scan tool) and monitor coolant temperature readings during a complete warm-up cycle to verify proper operation.

---

Disclaimer: This guide provides general troubleshooting information. Always consult the official Sany service manual and consider professional diagnostic assistance for complex electrical issues or if you're unfamiliar with high-voltage systems.