Volvo EC700B LC Fault Code 128PID1113: Technical Guide

What is Volvo EC700B LC Fault Code 128PID1113?

Fault Code 128PID1113 indicates a high voltage signal detected in the Crankcase Pressure (PID 1113) sensor circuit, with FMI 128 denoting a voltage above the normal operating range. This code means the Electronic Control Module (ECM) has detected an electrical signal from the crankcase pressure sensor that exceeds manufacturer specifications, typically above 4.5-5.0 volts on this Volvo D13 engine platform.

The crankcase pressure sensor monitors blow-by gases and pressure buildup inside the engine block. This is critical for the EC700B LC because excessive crankcase pressure can indicate serious internal engine wear, piston ring failure, or turbocharger issues. However, when code 128 appears with PID 1113, it most commonly points to an electrical fault rather than actual mechanical pressure problems—an important distinction for diagnostic efficiency.

Common Symptoms

• Engine derate mode activated, limiting machine to 75-80% power output
• Amber warning light illuminated on the instrument cluster, with possible audible alarm
• Stored fault code in ECM memory, retrievable through VCADS (Volvo Computer Aided Diagnostic System)
• No noticeable change in engine smoke or blow-by at crankcase breather (distinguishing electrical from mechanical issues)
• Intermittent code appearance during temperature changes or machine vibration, suggesting wiring problems

Potential Causes

On used Volvo EC700B LC excavators, this fault typically stems from:

• Damaged sensor wiring harness along the right side of the engine block where cables rub against the engine mount bracket (known wear point on D13 engines)
• Corroded or moisture-contaminated connector at the crankcase pressure sensor, especially on machines operated in coastal or high-humidity environments
• Failed crankcase pressure sensor itself, though less common than wiring issues in used equipment
• Chafed insulation on the signal wire creating intermittent short-to-voltage conditions
• ECM pin corrosion at connector terminals (rare, but documented on high-hour machines)

How to Troubleshoot and Fix Code 128PID1113

Step 1: Visual Inspection Locate the crankcase pressure sensor on the right-rear side of the engine block, near the flywheel housing. Disconnect the 3-pin Deutsch connector and inspect for oil contamination, bent pins, or green corrosion. On used excavators, this connector frequently accumulates moisture due to its low mounting position.

Step 2: Electrical Testing Using a digital multimeter, check the sensor signal wire (typically the middle pin). With the ignition on and sensor disconnected, you should read approximately 5.0 volts reference voltage from the ECM. If voltage reads higher than 5.2V, inspect the wiring harness from sensor to ECM for damaged insulation or improper routing against sharp edges.

Step 3: Sensor Resistance Check Measure sensor resistance across the signal and ground pins with ignition off. Specifications call for 200-5000 ohms depending on temperature. An open circuit (infinite resistance) indicates sensor failure. However, for used machines, first swap the sensor with a known-good unit before purchasing new—connector issues often mimic sensor failure.

Step 4: Harness Continuity Trace the harness along the engine block, checking for rub-through damage at the engine mount bracket and fuel filter housing. Use electrical tape and spiral wrap loom to protect repaired sections. For EC700B LC excavators with over 8,000 hours, consider replacing the entire engine harness section as preventive maintenance.

Step 5: Clear Code and Monitor After repairs, clear the fault using VCADS Pro or equivalent diagnostic software. Operate the machine through a full work cycle while monitoring live data for voltage spikes above 4.8V, which indicate intermittent faults requiring further harness investigation.

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Disclaimer: This guide provides general troubleshooting information. Always consult the official Volvo service manual and consider professional diagnostic services for complex electrical issues, especially on high-value equipment like the EC700B LC.