John Deere 523966.04 – PTR (PowrReverser Transmission module) / PRC: K10/2 - Come-Home Connector, Voltage Too Low During Test Routine

The system has detected that the voltage on the circuit for the transmission's "Come-Home" (limp mode) diagnostic plug is below the expected threshold during the module's self-test.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6125M
• 6135M
• 6140M
• 6130
• 6230
• 6330
• 6430
• 6530
• 6830
• 6930

1. 1

   Verify Plug Orientation: Check the K10/2 Come-Home plug located in the K10 relay box. If the plug is installed with the words "Come Home" at the top, the tractor has been manually placed into limp-home mode (which limits engine speed to 1500 RPM and restricts the transmission to first gear).

2. 2

   Circuit/Harness Test: Perform a multimeter continuity and voltage test on the "K10/02 - Come-Home Plug (PRC)" circuit. Check for a short to ground or an open circuit that would cause the voltage to drop too low during the module's test routine.

3. 3

   Inspect the Relay Box: Check the K10 relay box for moisture intrusion, blown fuses, or corroded terminals that could cause high resistance and a subsequent voltage drop.

4. 4

   System Voltage Check: Ensure the tractor's batteries and alternator are providing proper base voltage to the PTR/PRC module.

1. 1

   Power Down

   Turn off the engine and remove the key.

2. 2

   Locate the K10 Relay Box

   Access the tractor's main relay/fuse panel to locate the K10/2 Come-Home connector.

3. 3

   Correct the Plug Position (If Applicable)

   If the plug was intentionally or accidentally rotated 90 degrees to the "Come Home" position, remove the plug and re-install it rotated 90° back to its original, normal operating position.

4. 4

   Clean Contacts

   If the plug is in the correct position, remove it and inspect the pins. Spray the K10/2 connector and the K10 relay box receptacle with electrical contact cleaner to remove any corrosion or debris.

5. 5

   Repair Wiring

   If the diagnostic harness test revealed a short to ground, trace the wiring harness from the K10 relay box back to the PRC/PTR module. Repair any chafed wires or broken insulation using heat-shrink tubing and electrical tape.

6. 6

   Clear Codes

   Reconnect the plug, turn the key to the ON position, and use a diagnostic tool (or the tractor's onboard display) to clear the 523966.04 fault code. Test drive the tractor to ensure the code does not return and full transmission ranges are available.