Cummins Fault Code 195 indicates a problem with the engine coolant level sensor circuit, specifically a voltage reading that’s higher than normal. This fault code, often accompanied by an amber CHECK ENGINE light, can be triggered by various issues within the sensor circuit. Understanding this code is crucial for proper diagnosis and repair, ensuring your Cummins engine runs smoothly and avoids potential overheating problems.
Decoding Cummins Fault Code 195
Fault code 195, categorized as SPN 111 FMI 3, signifies an issue with the Engine Coolant Level Sensor 1 Circuit. The FMI (Failure Mode Indicator) 3 specifically points to a voltage above normal or a short to a high source. This means the Engine Control Module (ECM) is detecting a voltage exceeding 5.124 VDC for more than 20 seconds. While this fault doesn’t directly impact engine performance, it disables the low coolant level warning system, leaving your engine vulnerable to overheating.
How the Coolant Level Sensor Works
The coolant level sensor, located in the radiator top tank or surge tank, acts as a switch. It measures the coolant level and sends a varying voltage signal to the ECM. When submerged in coolant, the sensor’s resistance falls within a specific range (5.4k ohms to 34k ohms). When not submerged, the resistance significantly increases (333k ohms to 880k ohms). The ECM interprets these resistance changes as coolant level variations. A voltage above normal suggests a problem within the circuitry.
Diagnosing Cummins Code 195
Several factors can contribute to fault code 195:
- Open Circuit: A break in the wiring harness, connectors, or within the sensor itself can disrupt the signal, leading to a high voltage reading.
- Short Circuit: A short in the signal wire to the sensor supply or battery voltage can also cause an abnormally high voltage.
- Faulty Sensor: The coolant level sensor itself might be malfunctioning, providing inaccurate readings.
- ECM Issues: While less common, a problem with the ECM or its calibration could also be a contributing factor.
Troubleshooting Steps for Code 195
- Check Wiring and Connectors: Inspect the wiring harness and connectors for any damage, corrosion, or loose connections. Repair or replace as needed.
- Test the Sensor: Use a multimeter to test the sensor’s resistance. Compare the readings to the manufacturer’s specifications to determine if the sensor is functioning correctly.
- Verify ECM Calibration: Ensure the ECM has the latest calibration. Outdated calibrations can sometimes cause erroneous fault codes. Consult Cummins QuickServe® Online for calibration updates.
Resolving Cummins Fault Code 195
Addressing fault code 195 often involves:
- Repairing or Replacing Wiring: Damaged wiring or connectors should be repaired or replaced to restore proper signal transmission.
- Replacing the Sensor: If testing reveals a faulty sensor, replacement is necessary.
- Updating ECM Calibration: Updating the ECM to the latest calibration can resolve software-related issues contributing to the fault code.
Conclusion: Keeping Your Cummins Engine Cool
Cummins fault code 195 signals a potential issue with your engine’s cooling system. While not immediately performance-impacting, ignoring this code can lead to more serious problems down the road. By understanding the code, its causes, and the proper diagnostic steps, you can ensure your Cummins engine stays cool and operates reliably. If you lack the expertise or tools to diagnose and repair this issue, consult a qualified Cummins technician.
