John Deere 000976.04 – CCU / ACU: Rear PTO Sensor Voltage Problem

This fault code indicates a voltage problem within the rear Power Take-Off (PTO) system, specifically that the voltage in the circuit has dropped below the normal operational range. It is often described as a Rear PTO Sensor Voltage Problem. The low voltage condition prevents proper monitoring and control of the rear PTO system.

• 7020 Series
• 7030 Series
• 7630
• 7720
• 7730
• 7820
• 7830
• 7920
• 7930
• 8000 Series
• 8R Series
• 9030 Series
• 9230
• 9330
• 9430
• 9530
• 9630

1. 1

   Restart the tractor to see if the fault code is intermittent and clears upon a power cycle

2. 2

   Cycle the rear PTO switch off and then on again

3. 3

   Check overall system voltage by visually inspecting the batteries and alternator for damage, corrosion, or accumulated debris (low supply voltage can trigger this fault). In some cases of low supply voltage, reducing the electrical load or increasing the engine RPM may help.

4. 4

   Inspect the fuse box for any blown fuses related to the PTO or control units (e.g., Fuse F24 for the ECU or F22 for the CAB)

5. 5

   Check safety interlocks to ensure all conditions for PTO engagement are met, such as verifying the seat switch is not faulty

6. 6

   Inspect wiring harnesses and connectors leading to the rear PTO solenoid and sensors for obvious damage, loose connections, or corrosion

1. 1

   Read stored codes

   Connect to the tractor's diagnostic port using a tool like Service Advisor to read all active and stored codes from the CCU/ACU to get a complete picture of the issue.

2. 2

   Perform voltage and continuity tests

   Using a multimeter, test the voltage at the rear PTO speed sensor, solenoid, and related connectors to confirm the low voltage condition. Check for the appropriate 5V or 12V supply. Test the continuity of the wiring harness to identify any breaks or shorts.

3. 3

   Test PTO components

   Test the PTO solenoid for proper resistance (ohms) and listen for an audible click when power is applied. Monitor the PTO speed sensor's output while turning the PTO shaft by hand to check for a consistent signal. Test the console PTO switch for proper operation.

4. 4

   Replace faulty component

   Based on the diagnostic findings, replace the specific faulty component (sensor, solenoid, wiring harness section, or control unit).