CLAAS Id75CDh / 75CDh (314) – TR1 (A57-1) Transmission Module: Loss of the ENG module engine speed information.

The system logs this code when the transmission module loses the engine speed signal from the engine control unit over the CAN bus, specifically under the conditions that the control units are supplied with 12V after ignition and a theoretical vehicle speed of > 1 km/h is specified.

• CLAAS Ares (e.g., 507-607, 617 ATZ, 657 ATZ, 836-816)
• CLAAS Arion (e.g., 410-430, 500 series, 600 series, 610-640)
• CLAAS Axion (e.g., 800 series, 810-850)

1. 1

   Verify the integrity of the Powertrain CAN bus network communication lines between the modules

2. 2

   Check the connectors and the continuity of the wiring harnesses connecting the TR1 (A57-1) and ENG (A15) components

3. 3

   Verify the energy sources, including fuses, 12V power supply after ignition, and ground connections to the engine module

4. 4

   Check for potential short circuits or open circuits on the CAN network

5. 5

   Ensure the Engine Module ENG (A15) is functioning and transmitting data

1. 1

   Read Active Codes

   Connect a diagnostic computer to the tractor to confirm if the code is active or stored, and to check for accompanying CAN bus errors (such as BDG module errors).

2. 2

   Inspect Connectors

   Disconnect the 32-pin and 48-pin connectors at the ENG (A15) engine module (often an HPCR 14 type unit on DPS engines). Inspect for corrosion, pushed-out pins, or moisture.

3. 3

   Test Power and Ground

   With the ignition ON, verify that the ENG (A15) module is receiving a steady 12V supply and has a solid ground.

4. 4

   Test the Powertrain CAN Bus

   With the battery disconnected, measure the resistance across the CAN High and CAN Low pins to ensure the network is intact (standard CAN bus resistance should be checked for open circuits).

5. 5

   Repair/Replace

   If the wiring harness, fuses, and connectors test good, the fault lies within the ENG (A15) engine module failing to broadcast the engine speed message. The ECU will need to be sent out for repair or replaced and reprogrammed.