CLAAS Id7654h / 7654h (453) – Transmission Control Module (TR2 / Auto 5): No 20 bar low pressure information

An oil pressure fault within the transmission's low-pressure hydraulic circuit where the system fails to detect at least 20 bar of pressure when the engine is running above 500 RPM.

• CLAAS Arion 420
• CLAAS Arion 510
• CLAAS Arion 630C
• CLAAS Arion 640
• CLAAS Axion 810
• CLAAS Axion 850
• CLAAS Axion 920
• CLAAS Axion 950
• CLAAS Axion 960

1. 1

   Verify the actual hydraulic pressure of the low-pressure circuit to determine if the issue is mechanical or electrical

2. 2

   Inspect the low-pressure sensor (Z154) or the control pressure switch (Z201)

3. 3

   Test the Auto 5 / TR2 transmission module using the specialized CLAAS diagnostic tool (Tool No. 60 05 033 249)

1. 1

   Verify Operating Conditions

   Ensure the engine is running above 500 RPM, as the fault logic requires this threshold to monitor the 20 bar pressure.

2. 2

   Mechanical Pressure Test

   Connect a mechanical hydraulic pressure gauge to the transmission low-pressure test port. If the pressure is below 20 bar, troubleshoot the hydraulic circuit. If the pressure is at or above 20 bar, proceed to electrical diagnosis.

3. 3

   Inspect Wiring and Sensor

   Locate the low-pressure sensor (Z154) or control pressure switch (Z201). Inspect the wiring harness and connector for damage, corrosion, or open/short circuits.

4. 4

   Replace Sensor

   If the wiring is intact but the sensor is outputting an erratic or out-of-range signal (FMI 3 - Voltage too high is sometimes associated with this circuit), replace the Z154/Z201 sensor.

5. 5

   Test the ECU

   If the sensor and harness are functioning correctly, connect CLAAS diagnostic tool 60 05 033 249 to the TR2 (A57-2) / Auto 5 module to test its inputs/outputs.

6. 6

   Module Replacement

   If the module fails the diagnostic test with the tool, replace the transmission control module.