CLAAS Id75D1h / 75D1h (318) – TR1 (A57-1) Transmission Control Module: Loss of theoretical forward speed information or inconsistency

Loss of the theoretical forward speed information on the Powertrain CAN bus or inconsistency between the theoretical forward speed information on the Powertrain CAN bus and the information from the theoretical forward speed sensor.

• CLAAS Arion series (410, 420, 430, 510, 640)
• CLAAS Axion series (810, 850, 960)

1. 1

   Check the Powertrain CAN bus network and the CLAAS vehicle CAN bus network for proper resistance, voltage, and continuity

2. 2

   Check the theoretical forward speed sensor (B227) and its associated wiring harness and connectors

3. 3

   Check the instrument panel module (A101) and the CAN network communication module BDG (A103) to ensure they are transmitting messages properly

4. 4

   Check the Auto 5 (TR1) transmission module using the official CLAAS diagnostic tool (Tool No. 60 05 033 249)

1. 1

   Inspect Wiring

   Visually inspect the wiring harness and connectors leading to the B227 theoretical forward speed sensor for breaks, shorts, or corrosion.

2. 2

   Test the Sensor

   Start the engine and adjust the engine speed to 1150 rpm. Measure the output frequency (in Hz) of the B227 sensor across different gear ranges to ensure it matches OEM specifications (e.g., Range 1 should output approx. 101 Hz ± 3%, Range 2 approx. 120 Hz ± 3%, etc.).

3. 3

   Verify CAN Network

   If the sensor outputs the correct frequency, test the Powertrain CAN bus lines for shorts to ground or 12V, and ensure the instrument panel (A101) is successfully communicating with the transmission module.

4. 4

   Test/Replace the Control Module

   If the sensor, wiring, and CAN bus are all functioning correctly, connect CLAAS diagnostic tool n° 60 05 033 249 to test the "Auto 5" (TR1 / A57-1) module. If the module fails the diagnostic test, it must be replaced.