New Holland ENG 3801 – Engine ECU: Turbine upstream pressure sensor: SRC High for Turbine upstream pressure sensor

The signal voltage from the exhaust gas pressure sensor (which measures pressure upstream of the turbocharger turbine) is too high, typically pointing to a short circuit to the battery (B+) or an open circuit in the sensor wiring.

• L220
• L223
• L225
• L230
• C232
• C238
• SR175
• SR220
• SR250
• SV250
• SV300
• TR320
• TV380
• W50C
• W60C
• W70C
• W80C

1. 1

   Inspect the wiring harness between the exhaust gas pressure sensor and the Engine ECU for chafed wires causing a short to power (battery voltage) or a disconnected/open circuit.

2. 2

   Check the exhaust gas pressure sensor signal tube (the metal tube connecting the exhaust manifold to the sensor) for heavy soot blockages, cracks, or leaks.

3. 3

   Use a multimeter to verify the 5V reference supply, ground, and signal return at the sensor connector.

1. 1

   Turn off machine and disconnect battery

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the exhaust gas pressure sensor

   Locate the exhaust gas pressure sensor, typically mounted near the EGR valve or exhaust manifold.

3. 3

   Disconnect electrical harness

   Disconnect the electrical harness connector from the sensor.

4. 4

   Remove sensor signal tube

   Carefully loosen and remove the exhaust gas pressure sensor signal tube.

5. 5

   Remove faulty sensor

   Remove the faulty exhaust gas pressure sensor.

6. 6

   Install new sensor

   Install the new sensor.

7. 7

   Reinstall sensor signal tube

   Reinstall the exhaust gas pressure sensor signal tube. (Note: If the EGR flex pipe was removed for access, OEM manuals mandate replacing both EGR gaskets and torquing the flex pipe to 25 N·m / 18 lb ft).

8. 8

   Reconnect electrical harness

   Reconnect the electrical harness.

9. 9

   Clear fault codes and verify

   Reconnect the battery, turn the key on, and use a diagnostic service tool (like CNH EST) to clear the fault codes and verify the sensor reading is within normal parameters.