What is XCMG XE6D125-6D140-6D170 CM2350 Fault Code 153?

Fault Code 153 indicates an Engine Position Sensor Circuit Malfunction, specifically a signal voltage issue with the camshaft or crankshaft position sensor in the Cummins CM2350 engine. This code triggers when the Engine Control Module (ECM) detects an abnormal voltage range, intermittent signal loss, or complete failure from the position sensor circuit.

The engine position sensor is critical for proper fuel injection timing and engine synchronization on these XCMG excavators. The CM2350 engine relies on precise camshaft and crankshaft position data to optimize combustion timing, control fuel delivery, and manage emissions. When Code 153 activates, the ECM cannot accurately determine piston position, which directly impacts engine performance and can trigger protective derate modes to prevent mechanical damage.

Common Symptoms

• Check Engine Light (CEL) illuminated on the instrument cluster with potential engine derate to reduced power mode
• Hard starting or extended cranking time, especially when the engine is cold or after sitting overnight
• Rough idle or misfiring due to incorrect fuel injection timing caused by inaccurate position data
• Intermittent stalling during operation, particularly under load or when hydraulic systems are engaged
• Loss of power during digging or lifting operations as the ECM enters protective mode

Potential Causes

In used XCMG excavators with the CM2350 engine, Code 153 typically results from:

• Damaged or corroded wiring harness at common rub points near the engine block or transmission bell housing where vibration causes insulation wear
• Failed camshaft or crankshaft position sensor due to heat exposure, oil contamination, or internal component degradation common in high-hour machines
• Contaminated sensor connector pins from moisture intrusion, dirt, or oil seepage in the engine compartment
• Worn sensor mounting points causing excessive air gap between the sensor and reluctor wheel
• ECM internal circuit failure or corrupted software, particularly in machines with previous electrical system issues

How to Troubleshoot and Fix Code 153

Step 1: Visual Inspection Begin with a thorough visual examination of the sensor wiring harness from the ECM to both position sensors. On used excavators, check for harness chafing against the engine block, heat damage near exhaust components, and connector corrosion. Inspect the sensor mounting bolts for proper torque and verify the sensor face is clean and free from metallic debris.

Step 2: Electrical Testing Using a digital multimeter, check the sensor circuit voltage with the ignition on, engine off. The supply voltage should read 8-12 volts DC. Measure sensor resistance (typically 200-3000 ohms depending on sensor type) and compare to Cummins CM2350 specifications. Check for continuity in all wiring from sensor to ECM connector pins, and verify ground circuit integrity with less than 0.5 ohms resistance.

Step 3: Signal Analysis Connect Cummins INSITE diagnostic software or equivalent scan tool to monitor live sensor data. Crank the engine while observing the position sensor signal pattern—it should show consistent AC voltage pulses. Erratic signals or dropouts indicate sensor failure. On high-hour used machines, remove sensors and inspect the reluctor wheel teeth for damage or buildup.

Step 4: Component Replacement If testing confirms sensor failure, replace with OEM or high-quality aftermarket sensors designed for CM2350 engines. Apply dielectric grease to connector pins before reassembly. After installation, clear codes with diagnostic software and perform a sensor relearn procedure if required. Test operate under load to verify repair.

Disclaimer: This guide provides general troubleshooting information. Always consult the official XCMG service manual and Cummins engine documentation for exact specifications. For complex electrical diagnostics or ECM programming, professional consultation with a certified Cummins technician is recommended.