John Deere 524191.05 – CCU / PTQ: Voltage At the Air Brake Solenoid Is Low

The control module has detected an abnormally low voltage or current draw in the circuit supplying the trailer air brake solenoid valve. This condition typically points to an open circuit, a short to ground, a failing solenoid coil, or a damaged wiring harness preventing the valve from receiving adequate power.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC
• 7630
• 7730
• 7830
• 7930
• 7810
• 7210J
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R

1. 1

   Restart the tractor engine to verify if the active Diagnostic Trouble Code (DTC) reappears, as it may be a temporary communication message error.

2. 2

   Acknowledge the Service Alert by pressing the select switch on the CommandCenter to see if the display returns to normal mode.

3. 3

   Visually inspect the wiring harness around the batteries and alternator for any signs of physical damage, chafing, or accumulated debris that could cause a voltage drop.

4. 4

   Inspect system fuses (such as F12, F24, and F51, depending on the specific model's load center) to ensure none are blown.

5. 5

   Check the air lines and fittings for cracks or physical damage, which often accompanies wiring damage in the same area.

1. 1

   Park and secure the tractor

   Park the tractor safely, engage the parking brake, and turn off the engine.

2. 2

   Locate the valve

   Locate the trailer air brake valve and its solenoid on the tractor chassis.

3. 3

   Disconnect the harness

   Disconnect the wiring harness connector at the air brake solenoid.

4. 4

   Inspect the connector

   Inspect the connector pins for corrosion, moisture, or damage. Clean if necessary.

5. 5

   Test the voltage

   Test the voltage at the harness connector to verify if the low voltage condition is in the wiring harness or internal to the solenoid coil.

6. 6

   Remove the faulty valve

   If the valve/solenoid is faulty, relieve all air pressure from the system, disconnect the air lines, and unbolt the valve from its mounting location.

7. 7

   Install the replacement valve

   Install the replacement trailer air brake valve (a direct replacement design mounts in the original location without modifications).

8. 8

   Reconnect lines and connector

   Reconnect the air lines and plug in the electrical connector.

9. 9

   Bleed the system

   Bleed the air brake system properly and monitor the air gauge to ensure the system is holding pressure without leaks.

10. 10

    Restart and verify

    Restart the tractor. If the code persists, OEM manuals state you must have a John Deere dealer repair the circuit using Service ADVISOR diagnostic software.