New Holland ENG 3174 – ENGINE: Combustion Chamber Temperature Sensor: Out of Voltage - High

This fault code indicates that the voltage signal from the combustion chamber temperature sensor is exceeding the maximum expected threshold. In electrical diagnostics, an "Out of Voltage - High" condition typically points to an open circuit (such as a disconnected or broken wire) or a short to a power source within the sensor or its wiring harness.

• L220
• SR175
• SR130
• SR160
• Boomer 33
• Boomer 37

1. 1

   Locate the combustion chamber temperature sensor (B-9005) near the ARD/DOC/DPF assembly and check the connector for loose connections, backed-out pins, or corrosion.

2. 2

   Inspect the wiring harness leading from the Engine ECU to the sensor for chafing, breaks, or melted insulation that could cause an open circuit or a short to voltage.

3. 3

   Disconnect the sensor and use a multimeter to check the reference voltage from the ECU.

4. 4

   Test the sensor's internal resistance to see if it reads as an open circuit (infinite resistance), which would confirm internal sensor failure.

1. 1

   Power Down

   Turn off the machine and disconnect the negative battery cable to ensure safety and prevent electrical spikes.

2. 2

   Locate the Sensor

   Find the B-9005 Combustion Chamber Temperature Sensor on the exhaust/emissions aftertreatment assembly.

3. 3

   Disconnect

   Unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Carefully unscrew the temperature sensor from the combustion chamber housing. Apply penetrating oil if the sensor is seized due to high exhaust heat.

5. 5

   Install the New Sensor

   Thread the new sensor into the housing and tighten to the OEM torque specification.

6. 6

   Reconnect

   Plug the electrical connector back into the sensor, ensuring it clicks securely into place.

7. 7

   Clear Codes

   Reconnect the battery, turn the key to the ON position, and use a diagnostic scan tool to clear the ENG 3174 fault code. Start the engine and verify that the code does not return.