CLAAS Id76B5h / 76B5h (732) – REH (A58): Signal voltage of the left load sensor non valid.

The control unit is receiving an out-of-range, erratic, or missing electrical signal from the left draft/load sensing pin on the rear three-point hitch. As a safety and operational precaution, the load control (draft control) and the transport damper functions are rendered inactive.

• Axion 800 Series
• Axion 850
• Axion 900 Series
• Axion 920
• Axion 950
• Arion 600 Series
• Arion 640
• Arion 400 Series
• Arion 410
• Arion 430

1. 1

   Inspect the left load sensor (B144-1) for physical damage

2. 2

   Check the connectors and the continuity of the wiring harness linking the left load sensor to the REH lifting module (A58)

3. 3

   Test the wiring for any short-circuits (to ground or power) or open circuits

4. 4

   Verify the sources of energy at the sensor connector, including fuses, the 5V reference supply, and the ground connection

5. 5

   Check the sensor's internal resistance and ensure it is mechanically adjusted/seated correctly in the linkage bracket without binding

6. 6

   Verify the condition of the REH lifting module and its connections

1. 1

   Relieve Tension

   Lower the rear three-point hitch fully to the ground to relieve all mechanical tension and weight from the draft sensing pins. Turn off the tractor.

2. 2

   Inspect the Connection

   Locate the left load sensor (B144-1), which acts as the mounting pin for the left lower link arm. Disconnect its electrical connector. Clean the contacts with electrical contact cleaner and inspect for bent pins, corrosion, or moisture.

3. 3

   Test the Harness

   Using a multimeter, turn the ignition on and verify that the sensor is receiving its reference voltage (typically 5V) and has a solid ground.

4. 4

   Replace the Sensor

   If the wiring tests good but the fault persists (indicating an internal failure of the sensor), remove the retaining bolt or circlip securing the left draft pin. Slide the faulty load sensor out of the lower link bracket.

5. 5

   Install the New Part

   Lubricate (if specified by the manual) and slide the new load sensor pin into place. Secure it with the retaining hardware and reconnect the electrical harness.

6. 6

   Calibrate the Hitch

   Turn on the tractor and clear the fault codes. You must perform a rear hitch calibration procedure via the tractor's terminal (CIS/CEBIS) so the REH module can learn the "zero-load" baseline voltage of the newly installed sensor.