Case IH P17 – Rear PTO / Drivetrain Controller: Differential Lock Output Open Circuit

This indicates that the tractor's electronic control system has detected a break in the electrical circuit (an open circuit) that supplies power or ground to the differential lock solenoid. This prevents the differential lock from engaging.

• MXM
• Case IH MXM Series (MXM 120, 130, 140, 155, 175, 190)
• Case IH MX / TG Series
• Case IH Maxxum Series

1. 1

   Inspect the wiring harness leading to the differential lock solenoid for broken wires, chafing, or disconnected plugs.

2. 2

   Disconnect the plug at the solenoid and check for severe corrosion, bent pins, or moisture, which can cause an open circuit reading.

3. 3

   Use a multimeter to measure the resistance (ohms) across the differential lock solenoid pins. An infinite reading (OL) confirms the solenoid coil has failed internally and is causing the open circuit.

4. 4

   Disconnect the tractor's battery for a short period to reset the electronic control systems and clear temporary glitches.

1. 1

   Locate the Solenoid

   Locate the differential lock solenoid on the hydraulic control valve block (refer to your specific model's service manual for the exact location on the valve stack).

2. 2

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent electrical shorts.

3. 3

   Remove the Faulty Solenoid

   Unplug the 2-terminal electrical connector from the solenoid. Unthread and remove the faulty solenoid cartridge from the hydraulic block. Have a catch pan ready, as a small amount of hydraulic fluid may leak.

4. 4

   Install the New Part

   Lubricate the O-rings on the new solenoid with clean hydraulic fluid. Thread the new solenoid into the valve block and tighten to OEM torque specifications.

5. 5

   Reconnect

   Plug the electrical harness back into the new solenoid. Reconnect the battery.

6. 6

   Clear Codes

   Use a CNH diagnostic tool to clear the P17 code from the Rear PTO/Drivetrain controller.

7. 7

   Test Operation

   Start the tractor and engage the differential lock to ensure the code does not return and the lock functions properly.