John Deere PTQ524191.05 – PTQ: Trailer Air Brake Valve Problem

The system has detected a problem with the trailer air brake valve, specifically low voltage at the air brake solenoid located on the rear chassis. This indicates an electrical issue within the trailer brake system's control circuit.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 7630
• 7730
• 7830
• 7930

1. 1

   Restart the tractor to see if the communication error clears

2. 2

   Inspect the wiring harness leading to the trailer air brake solenoid for chafing, pinching, or frayed wires

3. 3

   Check the 7-pin trailer connector and the solenoid connector for corrosion, dirt, or loose pins

4. 4

   Examine the batteries and alternator area for damage or debris

5. 5

   Inspect fuses related to the transmission and chassis control units (specifically F9, F22, F12, F24, and F51)

6. 6

   Test voltage at the air brake solenoid's electrical connector while energized (should be approximately 12V)

7. 7

   Listen for audible hissing sounds around the air brake valve and use soapy water to check for air leaks

8. 8

   Bleed any excess moisture from the air brake reservoir

1. 1

   Isolate the fault

   Test the wiring harness for continuity and resistance to determine if the low voltage is caused by a wiring issue (short or open circuit) or a faulty solenoid.

2. 2

   Repair wiring

   If a wiring fault is identified during testing, repair or replace the damaged section of the harness.

3. 3

   Replace solenoid

   If the wiring is intact but the solenoid has high internal resistance or an internal short, replace the air brake solenoid.

4. 4

   Clear codes and retest

   After repairs are complete, clear the fault codes from the control unit's memory and retest the system to ensure the problem is resolved.