What is XCMG General Fault Code E1170?

Fault Code E1170 indicates an Engine Speed Sensor Circuit Malfunction or Signal Abnormality. This diagnostic trouble code (DTC) is triggered when the Electronic Control Module (ECM) detects an irregular, intermittent, or missing signal from the engine speed sensor (also known as the crankshaft position sensor).

In XCMG excavators, this sensor is critical for monitoring engine RPM and crankshaft position, which directly affects fuel injection timing, ignition sequencing, and overall engine performance. When the ECM cannot accurately read engine speed, it may default to limp mode or fail to start altogether. For used machines, this code often stems from sensor degradation, wiring damage, or connector corrosion rather than ECM failure.

Common Symptoms

When Code E1170 is active, operators typically experience:

• Engine cranks but fails to start, or starts and immediately stalls
• Check Engine Light (CEL) or malfunction indicator lamp illuminated on the dashboard
• Erratic engine RPM readings or tachometer fluctuations during operation
• Loss of power or engine entering derate mode (reduced performance to protect components)
• Intermittent stalling during idle or under load, especially when the machine is hot

Potential Causes

The most common technical reasons for E1170 in used XCMG excavators include:

• Worn or failed engine speed sensor due to heat exposure, vibration, or age-related deterioration
• Damaged sensor wiring harness, particularly at rub points near the engine block or flywheel housing
• Corroded or loose electrical connectors at the sensor or ECM interface
• Incorrect air gap between the sensor and crankshaft reluctor wheel (typically 0.5–1.5mm spec)
• ECM software glitches or outdated firmware requiring recalibration
• Damaged reluctor wheel teeth on the crankshaft (rare but possible in high-hour machines)

How to Troubleshoot and Fix Code E1170

Step 1: Visual Inspection
Locate the engine speed sensor (usually mounted near the flywheel or front crankshaft pulley). Inspect the wiring harness for abrasion, cuts, or melting, especially where it routes near hot exhaust components or moving parts. Check all connectors for corrosion, bent pins, or moisture intrusion—common issues in used excavators exposed to harsh environments.

Step 2: Electrical Testing
Using a digital multimeter, measure the sensor's resistance (typically 200–1000 ohms, but verify XCMG specifications). Disconnect the sensor and check for continuity in the wiring from the sensor connector to the ECM. Test the supply voltage (usually 5V or 12V reference) from the ECM to ensure proper power delivery.

Step 3: Sensor Air Gap and Physical Condition
Verify the air gap between the sensor tip and the reluctor wheel using feeler gauges. An incorrect gap causes weak or erratic signals. Inspect the reluctor wheel for missing or damaged teeth. For used machines, carbon buildup or metal shavings can also interfere with the magnetic field.

Step 4: Component Replacement and Calibration
If testing confirms sensor failure, replace with an OEM or high-quality aftermarket sensor. After installation, clear the fault code using XCMG diagnostic software or a compatible scan tool. Perform a crankshaft relearn procedure if required by the ECM to ensure accurate signal recognition.

Disclaimer: This guide is intended for informational purposes. Always consult XCMG service manuals and certified technicians for complex diagnostics, especially on used equipment with unknown maintenance history.