CLAAS Id75F6h / 75F6h (355) – TR1 (A57-1) Transmission Control Module / Auto 5: Short circuit on range B sensor

The transmission control unit has detected an electrical short circuit in the sensor circuit responsible for monitoring the engagement of the "B" gear range. When this fault is active, the system does not trigger an audio warning or request an "ISC" reset, but it can restrict transmission shifting.

• Axion 800 Series (e.g., 850)
• Arion 600 Series (e.g., 610, 630, 640)
• Arion 500 Series
• Arion 400 Series (e.g., 410, 420, 430)
• Ares Series (e.g., 656, 657, 697)

1. 1

   Test the B range engaged contact (Z153-2), as well as the A (Z153-1), C (Z153-3), and D (Z153-4) range contacts, since they share a harness and a short in one can affect the others

2. 2

   Check the 'Auto 5' transmission fuse to verify if it is blown, as a short circuit can disrupt voltage control to the module

3. 3

   Perform a mechanical inspection for a possible problem or seizure on the transmission range module synchronizers and forks

4. 4

   Test the 'Auto 5' module using CLAAS special diagnostic tool n° 60 05 033 249

1. 1

   Inspect the Wiring Harness

   Visually and electrically inspect the wiring harness connecting the TR1 (A57-1) module to the Z153 range switch assembly. Look for rubbed wires, pinched harnesses, or corrosion at the connectors that could cause a short to ground or power.

2. 2

   Test the Sensor Voltage

   Back-probe the Z153-2 (Range B) switch. According to the Arion technical systems manual, the correct operating parameters are: 0 V when Range "B" is engaged (Engine started), and 12 V when Range "B" is not engaged.

3. 3

   Replace the Fuse

   If the circuit was shorted, locate and replace the blown "Auto 5" transmission fuse.

4. 4

   Replace the Sensor

   If the wiring is intact but the Z153-2 switch fails to toggle between 0V and 12V (or is internally shorted), replace the Z153 gear box sensor.

5. 5

   Test the Transmission Module

   If the sensor and wiring are perfectly functional, the fault may lie within the TR1 (A57-1) module itself. Connect CLAAS tool 60 05 033 249 to test the module's internal circuitry. If the module fails the test, replace and reprogram the "Auto 5" module.