John Deere 739.05 – PTQ (PowrQuad Transmission Control Unit): Transmission Clutch/Range Solenoid Circuit Open or Current Below Normal

Indicates an open circuit or abnormally low current in a specific transmission clutch/range solenoid circuit. The transmission control unit detects that it cannot electrically command the solenoid, which often results in the transmission defaulting to Neutral, entering Park mode, or limiting gear selection to prevent damage.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6M series (6110M-6195M)
• 6R series (6110R-6215R)
• 6010-6910 models
• 7R series
• 7020 series
• 7030 series (7230, 7630, 7730, 7830)
• 8R series (8245R-8400R)
• 8RT series (8310RT-8360RT)
• 310SK
• 315SK
• 210K EP

1. 1

   Inspect the wiring harness running from the PTQ/PTP module to the transmission valve block for chafed wires, broken lines, or debris

2. 2

   Disconnect the specific clutch solenoid (C3, D-Clutch, or Y6) and check the connector pins for corrosion, moisture, or pushed-out terminals

3. 3

   Use a multimeter to measure the resistance across the solenoid coil pins (an infinite/OL reading confirms the coil has failed internally)

4. 4

   Turn the key ON and verify that the control module is sending the proper reference voltage to the solenoid connector when the specific gear/range is commanded

1. 1

   Prep the Machine

   Park the vehicle on a level surface, engage the parking brake, and turn off the engine. Relieve any residual hydraulic pressure before servicing transmission valves.

2. 2

   Locate the Solenoid

   Locate the transmission control valve block on the side of the transmission housing and identify the specific solenoid (C3, D, or Y6).

3. 3

   Remove the Faulty Component

   Disconnect the electrical plug. Depending on the valve design, either remove the retaining nut to slide the electromagnetic coil off the valve cartridge, or unbolt the entire solenoid valve assembly from the block.

4. 4

   Install the New Part

   Install the replacement solenoid valve or coil. Ensure the O-rings are lubricated with clean hydraulic fluid if replacing the cartridge.

5. 5

   Reconnect and Clear

   Reconnect the wiring harness. Start the tractor and use the CommandCenter display (or a diagnostic tool) to clear the PTQ/PTP codes.

6. 6

   Calibrate

   Bring the transmission fluid up to operating temperature and perform a Transmission Calibration procedure. This is highly recommended after replacing shift elements to ensure proper fill pressures and smooth shifting.