Fendt 10.1.36 – Air Conditioning Control ECU (A053) or Central Electrical System ECU (A038): B071 - Sensor, output temperature

The output temperature sensor for the air conditioning system is registering as "Function non-operable" (typically due to a missing signal, open circuit, or short). When this fault is active, the tractor's air conditioning system defaults to running 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 200 Vario (V/F/P)
• Fendt 300 Vario (COM III, S4, Gen4)
• Fendt 400 Vario (COM III)
• Fendt 500 Vario (S4)
• Fendt 700 Vario (COM III, S4)
• Fendt 800 Vario (COM III, S4 - e.g., 822, 824, 826, 828)
• Fendt 900 Vario (COM III, S4 - e.g., 927, 930, 933, 936, 939)

1. 1

   Inspect the wiring harness at separation point X1536 (the direct electrical connector for the B071 sensor) for corrosion, backed-out pins, or wire chafing.

2. 2

   Access the tractor's diagnostic display (Varioterminal) to confirm, call up, and delete the fault code to see if it immediately returns.

3. 3

   Verify if the AC is actually locked in emergency mode to rule out a transient software glitch.

1. 1

   Locate the sensor

   The B071 output temperature sensor is located inside the cab, specifically within the air box situated in front of the steering column.

2. 2

   Access the air box

   Detach the air box assembly from its mounting points in front of the steering column.

3. 3

   Remove the cover

   Remove the cover of the air box to expose the internal HVAC components (this area also houses components M015 and M016).

4. 4

   Disconnect the sensor

   Disconnect the sensor at separation point X1536.

5. 5

   Replace the sensor

   Remove the faulty B071 sensor and install the replacement.

6. 6

   Reassemble and clear codes

   Reinstall the air box cover, remount the air box to the steering column, and clear the fault codes from the system.