CLAAS 75D6h – TR1 (A57-1): Clutch Position Signal Inconsistency

The TR1 (A57-1) transmission control module has detected an inconsistency between the signals from the clutch pedal position potentiometer (R73) and the clutch pedal end-of-travel switch (BOC) (Z152). This conflict occurs if the potentiometer reports the pedal as fully released while the switch is closed, if the switch indicates the pedal is not fully released while the reverser is in neutral, or if the reverser is not in neutral and the pedal is depressed more than 50% but the switch remains open.

• Arion 400 Series
• Arion 410
• Arion 430
• Arion 500 Series
• Arion 510
• Arion 530
• Arion 550
• Arion 600 Series
• Arion 620
• Arion 640
• Arion 650
• Axion 800 Series
• Axion 810
• Axion 850

1. 1

   Inspect wiring harnesses connected to the TR1 module and clutch sensors for damage, moisture, or loose connections.

2. 2

   Inspect the Clutch Pedal Position Potentiometer (R73) and its connector for corrosion, loose terminals, or moisture. Back-probe the signal wire for a smooth voltage change (approximately 0.9-1.0V fully depressed to 4.2-4.8V fully released) without sudden drops, spikes, or dead spots.

3. 3

   Test the 'BOC' Clutch Pedal Low Contact Switch (Z152) for continuity to ensure it changes state (from open to closed, or vice-versa) when the pedal reaches the end of its travel.

4. 4

   Check the Reverser Lever (S171) electrical signals to ensure it correctly reports its position (Forward, Reverse, Neutral) to the transmission controller.

5. 5

   Check for a short circuit to 12V on the TR1 module harnesses or an open circuit on the end-of-travel switch harness, and inspect the wiring loom for any signs of abrasion, pinching, or damage.

1. 1

   Replace potentiometer

   If the clutch pedal position potentiometer (R73) is determined to be faulty based on the diagnostic checks, replace it.

2. 2

   Replace end-of-travel switch

   If the end-of-travel switch (Z152) is faulty, replace it.

3. 3

   Repair wiring

   Repair any identified wiring issues, such as short circuits or open circuits.

4. 4

   Perform clutch calibration

   After component replacement, perform a clutch calibration procedure specific to the tractor model (generally involving keying on the tractor, depressing the clutch, and using the shuttle lever in a specific sequence) so the transmission control module can learn the new sensor values and engagement points.

5. 5

   Clear codes and test

   Clear all fault codes from the control module memory and test the tractor to ensure the fault does not reappear.