CLAAS Id75C5h / 75C5h (306) – TR1 (A57-1) / Auto 5: Reverse Gear Solenoid Valve Return Circuit Current Too High

The actual current measured on the return circuit of the reverse gear solenoid valve is too high relative to the setpoint. This typically points to an internal short in the solenoid coil, a short-to-power in the wiring harness, or an internal failure within the control module's current measuring circuit.

• Arion 400 series
• Arion 410
• Arion 420
• Arion 430
• Arion 500 series
• Arion 510
• Arion 600 series
• Arion 640
• Axion 800 series
• Axion 810
• Axion 850

1. 1

   Test the 'Auto 5' module using the specific CLAAS diagnostic breakout tool/harness n° 60 05 033 249.

2. 2

   Inspect the wiring harness between the TR1 (A57-1) module and the reverse gear solenoid valve (Y328) for any 12V short circuits or melted insulation.

3. 3

   Check the resistance and current draw of the reverse gear solenoid valve to determine if the coil is internally shorted.

1. 1

   Isolate the Circuit

   Disconnect the reverse gear solenoid valve (Y328) and inspect the connector pins for corrosion, water ingress, or bridging.

2. 2

   Harness Testing

   Using a multimeter, test the return wire from the solenoid back to the TR1 (A57-1) module for a short to voltage.

3. 3

   Solenoid Replacement

   If the wiring is intact but the solenoid coil resistance is out of specification (causing the high current reading), drain the necessary transmission fluid, remove the faulty reverse gear solenoid valve from the transmission valve block, and install a new one.

4. 4

   Module Testing & Replacement

   If the solenoid and wiring test perfectly, the fault lies within the TR1 (A57-1) 'Auto 5' module's internal current measuring circuit. Connect the CLAAS diagnostic tool (60 05 033 249) to verify the module's outputs. If the module is outputting incorrect values or falsely reading high current, replace the 'Auto 5' unit.

5. 5

   Calibration

   Clear the fault codes via the CLAAS Diagnostic System (CDS) and perform any necessary transmission calibration routines before test-driving the tractor.