John Deere 521935.12 – GPM: INFORMATION FOR OPERATOR: Range A Jumped Out.

This code is generated when the transmission control software detects that "Range A" has disengaged unexpectedly during operation.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6140R
• 6150R
• 6170R
• 6190R
• 6210R

1. 1

   Attempt to re-engage Range A as an initial operator action

2. 2

   Check for related electrical fault codes such as 521935.05 (open circuit) or 521935.06 (short circuit)

3. 3

   Inspect the wiring harness and connectors leading to the Range A solenoid for damage, corrosion, or open/short circuits

4. 4

   Verify that the GPM control unit is receiving a stable power supply

5. 5

   Ensure the GPM/RPM control software is updated to the latest version to rule out software bugs

6. 6

   Inspect the transmission for mechanical issues such as wear, damage, or misalignment if electrical systems are sound

1. 1

   Clear and Retest

   Clear the fault code, operate the tractor, and attempt to engage Range A to see if the code returns.

2. 2

   Electrical Repair

   If wiring damage is found during diagnostics, repair the harness. If the Range A solenoid tests out of specification (shorted or open), replace the solenoid.

3. 3

   Cooling Phase Reset

   If the control unit detected excessive current or temperature, it may enter a 30-second cooling phase where shifting is disabled. Allow the system to cool and ensure transmission coolers/ventilation are functioning.

4. 4

   Mechanical Repair (Internal)

   If the transmission continues to jump out of Range A and the solenoid is functioning properly, the issue is internal. You will need to split the tractor and access the Range Transmission module.

5. 5

   Component Replacement

   Inspect the Range A shift forks, synchronizers, and gear dogs for rounding or excessive wear. Replace any worn mechanical shift components that are failing to hold the range under load.

6. 6

   Recalibration

   After replacing solenoids or internal transmission components, reinstall the software and perform a transmission calibration procedure via the John Deere Service ADVISOR tool.