John Deere 001058.18 – BCU / CCU: Air Brake Pressure Too Low

The system has detected that the air brake pressure is too low or there is a failure in the sensor associated with the main control module. This condition indicates that the pressure data is valid but below the normal operating range, which may affect the proper operation of the braking system.

• 7430 Premium
• 7530 Premium
• 6430
• 5430i

1. 1

   Allow pressure to build at startup (wait over a minute) to ensure there is sufficient air pressure to disengage the trailer brakes

2. 2

   Bleed moisture from the air brake reservoir by draining the air tank

3. 3

   Conduct a visual inspection of the air brake system for air leaks, listening for hissing sounds around the air tank, lines, and pressure sensor

4. 4

   Inspect electrical terminals for visible corrosion, loose or disconnected wiring connectors, and cracks in the sensor's body

5. 5

   Monitor the vehicle's air pressure gauge during startup and operation for erratic behavior, which could indicate a faulty sensor sending inconsistent signals

6. 6

   Check for other active diagnostic trouble codes from the control units to provide additional context

1. 1

   Address low pressure leaks

   If diagnostic checks indicate a genuine low-pressure condition (e.g., audible leaks, slow pressure buildup), identify the source of the leak and replace faulty air lines, fittings, or other components of the air brake system.

2. 2

   Test the pressure sensor

   If no air leaks are found and the pressure appears to be normal, use a multimeter to test the electrical continuity of the air brake pressure switch. Replace the sensor if it is suspected to be faulty.

3. 3

   Clear fault codes

   After performing any repairs, clear the diagnostic trouble codes from the control unit's memory.

4. 4

   Verify the repair

   Operate the machine and check if the fault code reappears. If the code returns, further diagnosis by a qualified technician may be required.