John Deere 629.06 – PL1 Transmission Controller: Control Unit, Current Too High

The system detects that the current draw in the control unit for gear shifting is excessively high, which typically indicates a short circuit in the system or a failing solenoid drawing too many amps. Because of the high amperage, the module overheats, shuts down to protect itself, and attempts to reset after 1 minute.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6105R
• 6115R
• 6125R
• 6135R
• 6140R
• 6150R
• 6170R
• 6190R
• 6210R

1. 1

   Test the resistance (ohms) of the gear shift and park lock solenoids on the DirectDrive transmission to check for an internally shorted coil.

2. 2

   Inspect the transmission wiring harness connecting the PL1 module to the gear shift solenoids for chafed wires, melted insulation, or pinched lines shorting to the tractor chassis.

3. 3

   Verify the tractor's charging system is not overcharging, as voltage spikes can cause module overheating.

4. 4

   Verify if the PL1 control software is up-to-date, as internal software faults can sometimes misreport current limits.

1. 1

   Power Down

   Disconnect the tractor's battery to prevent further electrical damage during testing.

2. 2

   Test and Replace Solenoids

   Disconnect the gear shift solenoids at the transmission. Using a multimeter, check the resistance of each solenoid. Replace any solenoid that tests out of OEM specification (shorted/low resistance).

3. 3

   Repair Wiring

   If the solenoids test fine, trace the wiring harness back to the PL1 controller. Repair or replace the harness if any bare wires are found shorting against the transmission housing.

4. 4

   Replace the PL1 Module

   If the wiring and solenoids are in perfect condition, the PL1 Transmission Controller itself has suffered an internal hardware short and must be replaced.

5. 5

   Reprogram and Calibrate

   If the PL1 controller is replaced, the new module must be flashed with the latest John Deere control software and the DirectDrive transmission must be recalibrated using John Deere Service Advisor.

6. 6

   Clear Codes

   Reconnect the battery, clear the 000629.06 code, and perform a functional test of the gear shift system.