New Holland ENG 3843 – Engine Control Unit (ECU): Turbine Upstream Temperature Sensor: SRC low for turbine upstream temperature sensor

The Engine Control Unit (ECU) has detected that the voltage signal from the inline turbine temperature sensor has dropped below the acceptable threshold (less than 460 mV), indicating that the sensor's signal circuit is shorted to a ground source.

• L230
• C232
• W50C
• W60C
• W70C
• W80C

1. 1

   Verify with a diagnostic tool that fault code 3843 is currently active and not a stored historical code.

2. 2

   Inspect the electrical wiring and connectors between the exhaust gas temperature sensor and the ECU for chafed wires, melted insulation, or pinched harnesses that could cause a short to ground.

3. 3

   Disconnect the sensor and check the voltage on the harness side to ensure the ECU is sending the correct reference voltage.

4. 4

   Test the sensor itself for an internal short to ground.

5. 5

   If the wiring and sensor test fine, verify the condition of the Engine Control Unit (ECU), as the fault may lie within the module itself.

1. 1

   Cool Down

   Ensure the engine is turned off and the exhaust system has completely cooled down to prevent severe burns.

2. 2

   Locate the Sensor

   Locate the exhaust gas temperature sensor (upstream turbine). It is mounted directly on the exhaust manifold before the turbocharger.

3. 3

   Disconnect

   Carefully disconnect the electrical connector from the sensor.

4. 4

   Removal

   Unscrew and remove the exhaust gas temperature sensor from the exhaust manifold.

5. 5

   Installation

   Thread the new exhaust gas temperature sensor into the manifold. Tighten it to the manufacturer's specified torque.

6. 6

   Reconnect

   Reconnect the electrical connector to the new sensor.

7. 7

   Clear Codes

   Use a diagnostic service tool to clear the DTC 3843 from the engine ECU.

8. 8

   Test

   Start the engine, allow it to reach operating temperature, and verify that the fault code does not return.