Case CX130C Fault Code P1113 and Boost Temperature Sensor Diagnostics

[MikePhua]

The CX130C Excavator and Its Tier 4 Evolution
The Case CX130C hydraulic excavator is part of Case Construction’s C Series lineup, introduced in the early 2010s to meet Tier 4 emissions standards while improving fuel efficiency and operator comfort. Case, founded in 1842 and headquartered in Wisconsin, has long been a trusted name in earthmoving equipment. The CX130C, weighing approximately 13 metric tons, is powered by an Isuzu 4JJ1X engine and features advanced hydraulic systems and electronic diagnostics.
With thousands of units sold across North America, Europe, and Asia, the CX130C became a popular choice for contractors handling utility trenching, site prep, and roadwork. Its integration of electronic control modules and emissions systems, however, introduced new layers of complexity—especially when fault codes appear.
What Does Fault Code P1113 Mean
Fault code P1113 on the Case CX130C indicates a “Boost Temperature Sensor Circuit High Input.” This means the engine control module (ECM) is receiving a voltage signal from the boost temperature sensor that exceeds the expected range. The boost temperature sensor monitors the temperature of compressed air entering the engine after passing through the turbocharger and intercooler.
Key terms:

• Boost temperature sensor: Measures the temperature of air entering the intake manifold post-turbo.
  
• High input: A voltage signal that is too high, often caused by wiring faults, sensor failure, or connector issues.
  
• ECM (Engine Control Module): The computer that manages engine performance, emissions, and diagnostics.
  

This fault can trigger derating, increased fan speed, or even limp mode depending on severity and duration.
Common Causes of P1113 and Diagnostic Steps
Several factors can lead to a high input signal from the boost temperature sensor:

• Sensor failure due to heat cycling or contamination
  
• Damaged wiring harness or corroded connectors
  
• Short to voltage in the sensor circuit
  
• Faulty ECM interpretation or software glitch
  

To diagnose:

• Inspect the sensor for physical damage or contamination
  
• Use a multimeter to check voltage at the sensor connector (typically 5V reference, ground, and signal)
  
• Verify continuity from the sensor to the ECM
  
• Check for shorts to power or ground in the harness
  
• Use a scan tool to read live data and compare boost temperature readings to ambient and coolant temperatures
  

In one case, a technician in Ireland found that the sensor connector had moisture intrusion, causing intermittent high voltage spikes. Cleaning and resealing the connector resolved the issue without replacing the sensor.
Sensor Location and Replacement Procedure
On the CX130C, the boost temperature sensor is typically mounted near the intake manifold or intercooler outlet. It may be threaded into an aluminum housing and secured with a locking clip.
Replacement steps:

• Disconnect battery to prevent ECM damage
  
• Remove connector and inspect pins for corrosion
  
• Unscrew or unclip the sensor from its housing
  
• Install new sensor and torque to manufacturer specs
  
• Reconnect wiring and clear fault codes using a scan tool
  

OEM sensors are recommended for compatibility, though high-quality aftermarket options exist. Always verify part numbers and sensor calibration before installation.
Impact on Engine Performance and Emissions
A faulty boost temperature sensor can affect:

• Air-fuel ratio calculations
  
• Turbocharger efficiency
  
• Exhaust gas recirculation (EGR) operation
  
• Diesel particulate filter (DPF) regeneration timing
  

If the ECM believes the intake air is hotter than it really is, it may reduce fuel delivery, delay turbo boost, or alter timing—leading to sluggish performance and increased emissions. In Tier 4 engines, accurate sensor data is critical to maintaining compliance and avoiding costly downtime.
Preventive Measures and Long-Term Reliability
To prevent future sensor faults:

• Inspect connectors during routine service
  
• Use dielectric grease to seal electrical contacts
  
• Avoid pressure washing near sensor locations
  
• Monitor engine data regularly with diagnostic tools
  
• Replace sensors proactively every 3,000–4,000 hours if operating in harsh environments
  

One fleet manager in Texas reported that proactive sensor replacement reduced fault code incidents by 70% across his excavator fleet, improving uptime and reducing technician callouts.
Conclusion
Fault code P1113 on the Case CX130C excavator is a clear signal that the boost temperature sensor circuit is reporting abnormal voltage. While the issue may seem minor, it can cascade into performance loss, emissions non-compliance, and unnecessary downtime. By understanding the sensor’s role, performing targeted diagnostics, and maintaining electrical integrity, operators and technicians can keep their machines running smoothly. In today’s electronically controlled diesel engines, even a single sensor can make the difference between peak performance and costly delays.