Fendt 04.1.24 – Transmission Control System: Signal fault with the hand brake switch

The system detects a faulty switch or signal fault (such as an illogical open/closed state) with the hand brake switch (S015 or S080). This causes the hand brake automatic mode to become unavailable, the Tractor Management System (TMS) to automatically switch off, and in some models, 4WD to automatically engage as a safety precaution.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 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 series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series
• Farmer 400
• Favorit 700
• Favorit 900
• 700-900 SCR series
• 900 Vario COM III
• Fendt 309 Vario
• Farmer 240 S through 280 V

1. 1

   Verify the tractor's control voltage at the existing switch connection to prevent damage to electronic control modules

2. 2

   Inspect the wiring harness and connector for the S015/S080 switch for physical damage, corrosion, or loose connections

3. 3

   Test the magnetic switch for proper continuity ('OPEN/CLOSED' detection) when the handbrake is physically applied and released

4. 4

   Check if there are any active calibration errors (a faulty S015 switch will trigger an F17 abort code during clutch/transmission calibration)

1. 1

   Power Down

   Turn off the ignition and disconnect the tractor's battery to protect the transmission control module and other sensitive electronics.

2. 2

   Locate the Switch

   Locate the S015/S080 hand brake magnetic solenoid switch near the handbrake lever assembly.

3. 3

   Removal

   Unplug the wiring harness connector from the faulty switch. Remove the mounting hardware and extract the old switch.

4. 4

   Preparation

   Clean all mounting surfaces and electrical connections thoroughly. Apply dielectric grease to the new switch's electrical contacts to prevent moisture ingress and ensure consistent performance.

5. 5

   Installation

   Mount the new replacement switch and secure the hardware. Reconnect the wiring harness.

6. 6

   Clear Codes & Test

   Reconnect the battery and turn the ignition ON. Access the tractor's terminal to call up and delete the stored 04.1.24 fault code from the memory. Test the handbrake operation to ensure the TMS functionality is restored and the auto mode engages properly.