Fendt 7.1.08 – Enhanced Control Module (A002): Signal fault from S042 - Front PTO speed sensor 3 solenoid switch

The control module is detecting an irregular, missing, or out-of-range electrical signal from the switch responsible for monitoring the front Power Take-Off (PTO) speed sensor circuit.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Fendt Favorit 900 (Fav 900) - twin e-box version
• Fendt 900 Vario (including COM III models)
• Fendt Farmer 400 series
• Fendt Favorit 700 series

1. 1

   Consult the 'PTO's' circuit diagram in the Fendt workshop manual (specifically noting if your tractor is a twin e-box version) to trace the exact routing of the S042 switch.

2. 2

   Inspect the wiring harness and connector at the S042 switch for physical damage, chafing, dirt ingress, or corrosion.

3. 3

   Using a multimeter, test the S042 microswitch for proper continuity when mechanically actuated. Verify that the correct signal voltage is being sent back to the Enhanced Control Module (A002).

4. 4

   Connect the FENDIAS diagnostic tool to verify if the fault is currently active or stored, and check for any related bus faults (such as A004/A002 communication errors).

1. 1

   Safely park the tractor on level ground, turn off the engine, engage the parking brake, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the S042 Front PTO speed sensor 3 solenoid switch/microswitch near the front PTO assembly.

   Refer to the 'Component Location' section D in the Fendt workshop manual.

3. 3

   Carefully disconnect the electrical connector from the S042 switch.

4. 4

   Remove the retaining bolts or clips securing the faulty switch to the PTO housing/bracket.

5. 5

   Install the replacement S042 switch and secure it with the mounting hardware.

6. 6

   Reconnect the electrical harness, ensuring the connector clicks into place and is free of debris.

7. 7

   Reconnect the battery.

8. 8

   Turn the ignition on and use the tractor's terminal or the FENDIAS diagnostic tool to clear the stored 7.1.08 fault code.

9. 9

   Start the tractor and engage the front PTO to verify that the speed sensor signal is reading correctly and the fault code does not return.