John Deere 521933.05 – GPM (Gear Shift Module): Gear 4 Solenoid Current Too Low

Generated when the control software detects that the electrical current value at the solenoid for Gear 4 is below the expected threshold. This condition typically indicates an open circuit, which is usually caused by damaged wiring, a disconnected plug, or a failed/open solenoid coil.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6R Series
• 6190R
• 6R 145
• 6R 215

1. 1

   Connect a compatible diagnostic tool (such as John Deere Service ADVISOR or Jaltest) to read the GPM failure memory and monitor live current values to the transmission solenoids.

2. 2

   Visually inspect the wiring harness running from the GPM controller to the DirectDrive transmission valve block. Look for chafed wires, pinched harnesses, or disconnected plugs.

3. 3

   Disconnect the connector at the Gear 4 solenoid and check for corrosion, pushed-out pins, or moisture intrusion.

4. 4

   Using a multimeter, measure the resistance across the pins of the Gear 4 solenoid coil. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the internal coil is broken.

5. 5

   If the solenoid tests good, measure the continuity of the power and ground circuits from the GPM harness connector down to the solenoid connector to locate the break in the wire.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery terminal to prevent electrical spikes.

2. 2

   Access the Solenoid

   Locate the transmission control valve block on the DirectDrive transmission housing where the gear shift solenoids are mounted.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic tests revealed a broken wire or damaged connector, splice and heat-shrink the damaged wire, or replace the pigtail connector.

4. 4

   Replace Solenoid (If Applicable)

   If the Gear 4 solenoid coil failed the resistance test: Clean the area around the solenoid to prevent debris from entering the transmission. Disconnect the electrical connector. Remove the retaining bolts or snap ring holding the Gear 4 solenoid in place. Extract the faulty solenoid and discard its O-rings. Lubricate the O-rings on the new solenoid with clean transmission hydraulic fluid. Install the new solenoid and torque the fasteners to OEM specifications.

5. 5

   Reassembly & Clearing

   Reconnect the electrical connector and the battery. Use your diagnostic scan tool to clear the 521933.05 code from the GPM module.

6. 6

   Test Drive

   Start the tractor and perform a test drive, ensuring the transmission successfully shifts into and out of Gear 4 without triggering a timeout or jumping out of gear.