Case IH P22 – Electronic Management Unit (EMU) or Transmission/EDC (Electronic Draft Control) controller: 4WD Solenoid Stuck On

The system is detecting that the four-wheel-drive engagement solenoid is remaining in the activated (ON) position when it should be disengaged, which can be caused by a mechanical sticking of the valve itself or an electrical short in the wiring harness.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Maxxum Series
• Puma Series
• MX Series
• TG Series
• CVX Series
• CVX 170

1. 1

   Turn the keystart to the ON position, select manual FWD, and then turn the keystart OFF

2. 2

   Depress both brake pedals, turn the keystart ON, and momentarily crank the engine (no need to fully start)

3. 3

   Check if error P22 is displayed on the dash to determine if the fault is active or intermittent

4. 4

   If the error is not displayed, the tractor is okay or you are dealing with a possible intermittent fault

5. 5

   If the error is displayed, disconnect the FWD solenoid connector (C034)

6. 6

   Disconnect the Electronic Management Unit Connectors (C105 / C19)

7. 7

   Trace the wiring harness to check for an open circuit or a short to ground, and clean all connectors in the circuit

1. 1

   Wiring Repair

   If the diagnostic checks reveal a short or open circuit in the harness between the EMU and the solenoid, repair or replace the affected wiring/connector.

2. 2

   Solenoid Replacement

   If the wiring tests good, the 4WD solenoid valve is mechanically stuck or internally shorted and must be replaced. Remove the old solenoid from the transmission/MFD valve block and install the new OEM solenoid.

3. 3

   Clear Codes

   Disconnect the tractor's battery for a short period to reset the electronic control systems and clear the DTC. Alternatively, use a certified diagnostic tool to clear the code.

4. 4

   Calibration

   According to the MXM Series Calibration Guide, if a PWM solenoid valve is replaced, a Transmission/EDC Calibration Set Up Procedure must be performed to ensure proper shift quality and controller memory reset.