Case IH t86 – CFPS: Solenoid Valve Power Stage, Data Valid But Below Normal Range

This fault code indicates an electrical issue, such as a short to ground, low voltage, or an intermittent short circuit, affecting the power stage of a transmission pulse-width modulation (PWM) solenoid valve. It is logged by the Secondary Controller (CFPS) and can disrupt hydraulic flow control within the transmission.

• MXM
• MXM 120
• MXM 130
• MXM 135
• MXM 140
• MXM 150
• MXM 155
• MXM 165
• MXM 175
• MXM 180
• MXM 190

1. 1

   Turn the Power OFF and Keyswitch OFF, then disconnect the connectors at each end of the suspected solenoid circuit to prevent false readings.

2. 2

   Inspect fuse 12 in the fuse panel; a blown fuse strongly indicates a short circuit.

3. 3

   Set a multimeter to measure resistance (ohms). Connect the black lead to a clean, plated metal part on the chassis (ground). Use the red lead to probe the connector pins one at a time (avoid touching the metal case of the connectors).

4. 4

   Evaluate the harness for a short to ground based on the resistance test results.

5. 5

   If the harness tests okay, cycle the keystart OFF and ON, and verify that the controller has the correct and most up-to-date software downloaded.

1. 1

2. 2

   Secure the machine

   Park the tractor on level ground, place shift levers in neutral, lower all equipment, and block the front and rear wheels.

3. 3

   Repair harness and replace fuse

   If diagnostic checks revealed a short to ground, repair or replace the damaged section of the wiring harness and replace Fuse 12.

4. 4

   Replace transmission solenoid valve

   If the wiring is intact but the solenoid power stage is failing, replace the affected transmission PWM solenoid valve.

5. 5

   Replace Secondary Controller (CFPS)

   If the harness is good, software is updated, and the fault re-occurs after replacing the solenoid, the internal power stage of the ECU has failed. Remove and replace the Secondary Controller (CFPS).

6. 6

   Perform transmission calibration

   After replacing a PWM solenoid valve or the microprocessor, start the engine, set engine speed to 1200 ERPM, and initiate the H1 (Clutch Calibration) routine via the transmission service menu.