Fendt 10.1.37 – Air Conditioning Control ECU (A053) or Central Electrical System ECU (A038): B074 - Sensor, internal temperature (Interior temperature sensor)

The internal cab temperature sensor is malfunctioning, reading out of range, or has failed completely. The sensor's function becomes non-operable, which forces the tractor's air conditioning system to run in emergency mode.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III & SCR)
• Fendt 800 Vario (COM III & S4)
• Fendt 900 Vario (COM III & S4)
• Fendt 922
• Fendt 924
• Fendt 927
• Fendt 930
• Fendt 933
• Fendt 936
• Fendt 939

1. 1

   Locate separation point X1545, which is the electrical connector for the B074 sensor.

2. 2

   Visually inspect the wiring harness and connector pins for corrosion, moisture, or physical damage.

3. 3

   Measure the resistance across the sensor pins with a multimeter to check for an open-circuit (infinite resistance) or short-circuit (zero resistance), as the sensor is an NTC thermistor.

4. 4

   Test the continuity of the wiring between the X1545 connector and the Air Conditioning Control ECU to rule out a broken wire in the cab harness.

1. 1

   Turn off the tractor and disconnect the battery to prevent electrical shorts.

   Turn off the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the cab circulation air filter housing on the left side.

   Locate the cab circulation air filter housing on the left side.

3. 3

   Remove the cab circulation air filter to gain access to the ventilating shaft.

   Remove the cab circulation air filter to gain access to the ventilating shaft.

4. 4

   Locate the B074 internal temperature sensor and its electrical separation point (X1545).

   Locate the B074 internal temperature sensor and its electrical separation point (X1545).

5. 5

   Disconnect the X1545 electrical connector.

   Disconnect the X1545 electrical connector.

6. 6

   Unclip or unthread the faulty B074 sensor from its mounting point in the shaft.

   Unclip or unthread the faulty B074 sensor from its mounting point in the shaft.

7. 7

   Install the new interior temperature sensor and reconnect the X1545 plug.

   Install the new interior temperature sensor and reconnect the X1545 plug.

8. 8

   Reinstall the cab circulation air filter and secure the housing.

   Reinstall the cab circulation air filter and secure the housing.

9. 9

   Reconnect the battery, turn on the ignition, and use the tractor's onboard diagnostic terminal (or FENDIAS software) to clear the stored 10.1.37 fault code.

   Reconnect the battery, turn on the ignition, and use the tractor's onboard diagnostic terminal (or FENDIAS software) to clear the stored 10.1.37 fault code.

10. 10

    Test the HVAC system to ensure the air conditioning has exited emergency mode and regulates temperature correctly.

    Test the HVAC system to ensure the air conditioning has exited emergency mode and regulates temperature correctly.