CLAAS Id764Ah / 764Ah (443) – TR2 (A57-2) Transmission Control Module: Supply voltage measured on solenoid valve SV2 when the driver is not controlled (setpoint PWM = 0).

The control module is detecting a 12V supply voltage on the circuit for solenoid valve SV2 even though the module is commanding a 0% duty cycle (meaning the valve should be completely turned off). This indicates a short-to-power in the wiring harness or an internal fault within the control module keeping the circuit energized.

• Arion 410
• Arion 420
• Arion 430
• Arion 510
• Arion 610
• Arion 630
• Arion 640
• Axion 810
• Axion 850

1. 1

   Check for a possible 12 V short circuit on the solenoid valve SV2 (Y335-2) power supply harness

2. 2

   Verify the connectors and the continuity of the harnesses linking the TR2 module to the SV2 solenoid, looking for pinched wires, chafing, or melted insulation

3. 3

   Check the resistance of the SV2 solenoid valve to ensure it is not internally shorted

4. 4

   Test the Auto 5 (TR2) module using CLAAS diagnostic tool n° 60 05 033 249

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent accidental shorts during testing.

2. 2

   Locate Components

   Locate the TR2 (A57-2) Transmission Control Module and the SV2 (Y335-2) "Ratio under torque" solenoid valve on the transmission valve block.

3. 3

   Isolate the Circuit

   Disconnect the wiring harness connector at the SV2 solenoid and at the TR2 module.

4. 4

   Test for Short to Power

   Reconnect the battery and turn the key to the ON position (engine off). Use a multimeter to measure voltage on the SV2 supply pin at the harness connector. If 12V is present while the module is disconnected, the wiring harness has a short to power and must be repaired or replaced.

5. 5

   Test the Solenoid

   Measure the resistance across the pins of the SV2 solenoid valve. If it falls outside OEM specifications (or is shorted to ground), replace the solenoid valve.

6. 6

   Test/Replace the Module

   If the wiring harness is completely intact (no short to 12V) and the solenoid tests fine, the fault lies within the TR2 (Auto 5) module itself (internal driver shorted closed). Use CLAAS tool n° 60 05 033 249 to verify module failure. Replace the TR2 module if required.

7. 7

   Clear Codes

   Reconnect all components, clear the fault codes via the diagnostic interface, and test drive the tractor to ensure the transmission shifts correctly and the code does not return.