Case IH F1P – Transmission Controller: Reverse Range Solenoid Open Circuit Or Short To Ground

Indicates an electrical fault where the transmission controller detects that the circuit for the reverse range solenoid is either broken (open circuit) or has shorted out to the ground. When this code is active, the transmission status is typically 'Disabled,' meaning the tractor will not move or engage the affected clutch packs.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Maxxum
• Puma

1. 1

   Inspect the transmission extension harness and main harness for visible damage, rubbing, or disconnected plugs, particularly connector C040

2. 2

   Use a multimeter to check for continuity and resistance on the reverse range solenoid circuit to confirm an open wire or short to ground

3. 3

   Check controller current via diagnostic menus (should read 0 when off, and jump to a specific value like 750 when commanded on)

4. 4

   Check for related codes like F21 (Transmission Extension Harness To Main Harness Disconnected) which point to a broader harness issue

1. 1

   Secure the Machine

   Lower all equipment to the ground, place all shift levers in neutral, block the wheels (front and rear), and turn off the engine.

2. 2

   Locate the Solenoid

   Locate the reverse range solenoid on the transmission control valve block.

3. 3

   Disconnect and Inspect

   Unplug the electrical connector (C040) at the solenoid. Inspect the pins for corrosion, moisture, or pushed-out terminals.

4. 4

   Replace the Solenoid

   If the wiring tests good but the solenoid fails a resistance test, remove the retaining bolt/bracket holding the reverse range solenoid and pull the valve out of the transmission block. Install the new solenoid with new O-rings.

5. 5

   Reconnect and Clear Codes

   Plug the harness back in and turn the key on to verify the F1P code is no longer active.

6. 6

   Perform Transmission Calibration

   Anytime a PWM solenoid valve is replaced, the transmission clutches must be recalibrated to prevent an F24 error code. Hold the High and Low range buttons while starting the engine until 'CAL' appears on the display, set engine speed to 1200 RPM, and follow the on-screen prompts.