CLAAS Id76B8h / 76B8h (735) – REH (A58): The REH lifting module has not received the theoretical speed information for more than 1 second over the Powertrain CAN bus.

Because the speed data is missing, the tractor's load control and skid control functions become inactive. The system will default to using the last measured load value to prevent erratic hydraulic behavior.

• Axion 810
• Axion 850
• Axion 800-series
• Arion 410
• Arion 430
• Arion 510
• Arion 530
• Arion 550
• Arion 620
• Arion 640
• Arion 650

1. 1

   Check the Powertrain CAN bus network for continuity, shorts to ground/power, and proper terminating resistance

2. 2

   Check the Instrument Panel Module DBD (A101) to ensure it is broadcasting speed data

3. 3

   Check the Lifting Module REH (A58) physical connector pins and power/ground supply

1. 1

   Verify the CAN Bus Integrity

   Access the Powertrain CAN bus wiring. Test the CAN-High and CAN-Low lines for proper voltage (typically ~2.7V and ~2.3V respectively) and check the network resistance (should be ~60 ohms with the battery disconnected).

2. 2

   Inspect Harnesses and Connectors

   Inspect the wiring harness running between the REH (A58) module (usually located under the right-hand console) and the DBD (A101) instrument panel module. Look for chafed wires, corrosion, or backed-out pins.

3. 3

   Check for Concurrent Faults

   Connect the CLAAS Diagnostic System (CDS). Look for other active codes in the DBD (A101) module or transmission modules (TR1/TR2/TR3). If the transmission or radar speed sensors are failing, the DBD cannot send the theoretical speed to the REH. Fix any speed sensor or instrument panel faults first.

4. 4

   Test the DBD (A101) Module

   If the CAN bus is intact but speed data is not being broadcasted to the network, the instrument panel module may require a software update, reconfiguration via CDS, or replacement.

5. 5

   Replace the REH (A58) Module

   If the Powertrain CAN bus is healthy, the DBD is broadcasting correctly, and the wiring to the REH module is perfect, the internal CAN transceiver in the REH module has likely failed. Replace the A58 module.

6. 6

   Recalibrate

   After replacing the REH module, you must perform a rear lifting calibration using the diagnostic tool or the in-cab sequence to restore full functionality.