New Holland ENG 3802 – Engine ECU (EDC module): Turbine upstream pressure sensor: SRC low for turbine upstream pressure sensor

Signal Range Check Low. The Engine Control Unit has detected that the voltage signal from the exhaust gas pressure sensor (located upstream of the turbocharger turbine) has dropped below the minimum acceptable threshold. This is typically caused by a short to ground in the sensor wiring, an open circuit, or an internal failure of the sensor itself.

• L220
• L230
• C185
• SR175
• W50C
• W60C
• W70C
• W80C
• T4
• T5
• T6
• T7

1. 1

   Inspect the wiring harness and connector leading to the turbine upstream pressure sensor for chafed wires, melted insulation, corrosion, or disconnected pins

2. 2

   Disconnect the sensor and turn the key to the ON position to check the connector for the 5V reference signal and a good ground coming from the ECU

3. 3

   Inspect the metal signal tube/pipe connecting the sensor to the exhaust manifold to ensure it is not cracked, leaking, or clogged with soot/carbon buildup

4. 4

   If the wiring has a good 5V reference and ground, and the signal tube is clear, test the sensor itself as it has likely failed internally

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the negative battery cable. Allow the exhaust system to cool completely, as the sensor is located near the turbocharger and exhaust manifold.

2. 2

   Locate the Sensor

   Find the turbine upstream pressure sensor (exhaust gas pressure sensor) and its connecting signal tube near the exhaust manifold/EGR flex pipe area.

3. 3

   Disconnect Electrical

   Carefully unplug the electrical connector from the sensor.

4. 4

   Remove the Sensor

   Use a wrench to unscrew the sensor from the exhaust gas pressure sensor signal tube.

5. 5

   Clean/Inspect the Tube

   Inspect the signal tube for carbon blockage. If clogged, remove the tube, clean it thoroughly with a wire brush and parts cleaner, and reinstall it. (Note: If the EGR flex pipe is removed during this process, CNH mandates replacing both mounting gaskets).

6. 6

   Install New Sensor

   Thread the new exhaust gas pressure sensor onto the signal tube. Tighten to the OEM torque specification (do not overtighten, as the threads can be delicate).

7. 7

   Reconnect

   Plug the electrical connector back into the sensor.

8. 8

   Clear Codes

   Reconnect the battery. Use the CNH Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the ENG 3802 fault code.

9. 9

   Test Run

   Start the engine and verify that the code does not return and that the exhaust pressure readings are within normal parameters on the diagnostic tool.