New Holland ENG 3173 – Engine ECU: Combustion Chamber Temperature Sensor: Out of Voltage - Low

The Engine Control Unit has detected that the voltage signal from the Combustion Chamber Temperature Sensor has dropped below the minimum acceptable threshold, indicating a short circuit to ground in the wiring harness or an internal short within the sensor itself.

• L213
• L215
• L216
• L218
• L220
• L230
• C238
• SR130
• SR150
• SR160
• SR175
• SV185
• B90B
• B100B

1. 1

   Inspect the wiring harness leading to the combustion chamber temperature sensor on the aftertreatment (DPF/DOC) assembly for melted insulation, chafing against hot exhaust components, or pinched wires.

2. 2

   Unplug the combustion chamber temperature sensor and check active fault codes. If the code changes from 3173 to 3174 (Voltage High), the sensor is internally shorted. If it remains 3173, there is a short to ground in the wiring harness.

3. 3

   Inspect the sensor and ECU connector pins for corrosion, water intrusion, or bent pins.

1. 1

   Prep the Machine

   Park the machine on a level surface, turn off the engine, and disconnect the negative battery cable. Ensure the exhaust and aftertreatment system has completely cooled down before beginning work to prevent severe burns.

2. 2

   Locate the Sensor

   Locate the combustion chamber temperature sensor on the ARD (Aftertreatment Regeneration Device) / DPF burner assembly.

3. 3

   Disconnect

   Unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Carefully unscrew the sensor from the combustion chamber housing. Apply penetrating oil and allow it to soak if resistance is high to avoid stripping the threads.

5. 5

   Install the New Sensor

   Apply a small amount of high-temperature anti-seize compound to the threads of the new sensor (if it does not come pre-applied). Thread it in by hand to prevent cross-threading, then tighten to OEM torque specifications.

6. 6

   Reconnect

   Plug the electrical connector back in, ensuring the locking tab clicks into place. Secure any loose wiring away from direct heat sources.

7. 7

   Clear Codes

   Reconnect the battery, turn the ignition ON, and use a diagnostic tool (or the machine's instrument cluster) to clear the inactive 3173 fault code.

8. 8

   Test

   Start the engine and monitor the system to ensure the code does not return.