CLAAS Id7648h / 7648h (441) – TR2 (A57-2) Transmission Control Module (Auto 5): Solenoid valve SV3 return current less than setpoint

The actual current measured on the solenoid valve SV3 return is less than the setpoint value. The control module is commanding the SV3 solenoid valve to operate, but the electrical current returning from the valve is lower than expected. This typically indicates an open circuit, a short circuit to ground, a failed solenoid coil, or an internal failure within the control module itself.

• CLAAS Axion 800 Series (810, 850)
• CLAAS Arion 500/600 Series (510, 530, 550, 610, 620, 630, 640, 650)
• CLAAS Ares Series (657, 697 ATZ)

1. 1

   Check for a possible open circuit in the solenoid valve supply harness.

2. 2

   Check for a possible short circuit to earth (ground) on the solenoid valve harness.

3. 3

   Test the resistance and functionality of the solenoid valve SV3 (Component designation: Y335-3, which is the 'Ratio under torque solenoid valve').

4. 4

   Check the Auto 5 (TR2) transmission control module itself.

1. 1

   Inspect the Wiring Harness

   Locate the wiring harness running from the TR2 (A57-2) transmission module to the SV3 solenoid valve (Y335-3). Visually inspect the harness for chafing, pinched wires, or disconnected/corroded connector pins.

2. 2

   Test for Open/Short Circuits

   Disconnect the harness at both the module and the solenoid. Use a digital multimeter to test the wires for continuity (to rule out an open circuit) and check for continuity to ground (to rule out a short to earth). Repair or replace the wiring harness if faults are found.

3. 3

   Test the SV3 Solenoid Valve

   Measure the internal resistance of the SV3 (Y335-3) solenoid coil. If the resistance is out of specification (infinite resistance indicates a blown coil), the solenoid valve must be replaced.

4. 4

   Replace the Auto 5 Module

   If the wiring harness is intact and the SV3 solenoid tests perfectly, the fault lies within the TR2 (A57-2) 'Auto 5' control module failing to read the return current properly. Replace the Auto 5 module (Part No. 60 05 033 249) if the other checks pass.

5. 5

   Clear Codes and Test

   After repairing the wiring or replacing the faulty component, clear the fault codes and test the transmission functions to ensure the error does not return.