Deutz-Fahr 455 – ECU: Fan Actuator Circuit Open or Cable Break

The Engine Control Module (ECU) has detected a loss of electrical connection or an abnormally low current draw from the fan actuator (PWM output). This indicates a cable break, a faulty connector, or an internal failure of the fan actuator itself, preventing proper engagement and control of the engine's cooling fan.

• Agrotron 108
• Agrotron 118
• Agrotron 120
• Agrotron 128
• Agrotron 130
• Agrotron 140
• Agrotron 150
• Agrotron 150.7
• Agrotron 155
• Agrotron 165
• Agrotron 165.7
• Agrotron Profiline 120
• Agrotron Profiline 130
• Agrotron Profiline 150
• Agrotron Profiline 150.7
• Agrotron Profiline 165.7
• Agrotron Profiline 180.7
• Agrotron TTV 1130
• Agrotron TTV 1145
• Agrotron TTV 1160

1. 1

   Visually inspect the wiring harness leading to the fan actuator (clutch) for chafing, breaks, or corrosion

2. 2

   Disconnect the electrical connector at the fan clutch and inspect the pins and sockets for corrosion, dirt, damage, or fretting from vibration

3. 3

   Inspect the fuse box for any blown fuses related to the engine control or fan circuit

4. 4

   If a diagnostic tool (like Deutz SerDia) is available, command the fan to turn on to confirm the fault is present

1. 1

   Turn keyswitch OFF

   Ensure the vehicle's ignition is off and the engine is stopped before proceeding with any electrical tests or repairs.

2. 2

   Test the circuit for open or short

   With the fan clutch and ECU disconnected, use a multimeter to check for continuity on the control wire between the ECU connector and the fan clutch connector (infinite resistance indicates a broken wire). Check for a short to ground by measuring resistance from the PWM signal wire to a known good chassis ground. Check for a short to power by measuring voltage on the signal wire at the fan clutch connector with the keyswitch ON (there should be no voltage until commanded by the ECU).

3. 3

   Repair wiring and connectors

   If a wiring fault (open or short) is found, repair the damaged section of the harness and ensure it is insulated. Clean any corroded connector pins with contact cleaner, or replace the connector if necessary.

4. 4

   Test the fan actuator (clutch)

   If wiring and connectors are in good condition, measure the resistance across the clutch coil pins. A reading of infinite resistance confirms an internal open circuit within the clutch.

5. 5

   Replace the fan actuator

   If the viscous fan clutch is determined to have an internal open circuit or is otherwise faulty, replace it with a new unit.

6. 6

   Clear fault codes and verify repair

   Reconnect all components. Use a diagnostic tool to clear the fault code from the ECU's memory. Start the engine and allow it to reach operating temperature, or command the fan on via the diagnostic tool, to verify the fan engages correctly and the code does not return.