CLAAS Id75C1h / 75C1h (302) – TR1 (A57-1) Transmission Control Module: Inconsistent current measurements obtained on the reverse gear solenoid valve.

The system receives a different value from each of the two measuring points on the return circuit. Because of this inconsistency, the transmission's "Auto 5" electronic unit defaults to working with an estimated current to maintain basic functionality. This fault does not trigger an audio warning or request an "ISC" reset.

• CLAAS Axion 800 Series
• Axion 810
• Axion 850
• CLAAS Arion 600 Series
• Arion 610
• Arion 630
• Arion 640
• CLAAS Arion 400 Series
• Arion 410
• Arion 420
• Arion 430

1. 1

   Check the connectors and the continuity of the harnesses connecting the reverse gear solenoid valve to the TR1 module

2. 2

   Check for a possible 12V short-circuit or an open circuit on the solenoid valve power supply harness

3. 3

   Measure the resistance of the reverse gear solenoid valve winding

4. 4

   Verify all sources of energy, including fuses, power supply, and ground connections

5. 5

   Test the Auto 5 electronic control unit using the official CLAAS diagnostic tool (Tool n° 60 05 033 249)

1. 1

   Visual Inspection

   Inspect the wiring harness leading to the reverse gear solenoid valve for chafing, melting, or corrosion at the connector pins.

2. 2

   Electrical Testing

   Using a multimeter, perform a continuity test on the return circuit wires to identify where the inconsistent measuring points are losing signal.

3. 3

   Solenoid Winding Test

   Disconnect the reverse gear solenoid valve and measure its internal resistance. If the resistance is out of specification (indicating a degraded coil), the valve must be replaced.

4. 4

   Auto 5 Module Verification

   If the wiring and solenoid valve are in good condition, connect CLAAS Tool n° 60 05 033 249 to the "Auto 5" module to run an internal electronics test.

5. 5

   Replacement

   Replace the reverse gear solenoid valve if it fails the resistance test. If the diagnostic tool flags the control unit, replace the "Auto 5" module.