Case IH F29 – Transmission Controller: 19th Gear Clutch Solenoid Over Voltage

This fault code indicates that the voltage supplied to or sensed at the 19th gear clutch solenoid is too high. This underlying condition typically points to a "short to power" in the wiring harness, an internal short within the solenoid itself, or a malfunction within the transmission controller sending excessive voltage.

• MXM
• Case IH MXM 120
• Case IH MXM 130
• Case IH MXM 140
• Case IH MXM 155
• Case IH MXM 175
• Case IH MXM 190
• Case IH Magnum Series
• Case IH Puma Series

1. 1

   Verify the Code: Enter the tractor's Transmission Service Menu (H-Menu) by holding the upshift and downshift buttons while starting the tractor. Navigate to the HD menu to view live error codes and HB to view stored codes to confirm F29 is active.

2. 2

   Check Battery and Alternator Voltage: Ensure the tractor's system voltage is within normal operating parameters (approx. 12-14V). Overcharging can sometimes trigger over-voltage codes.

3. 3

   Inspect the Wiring Harness: Thoroughly inspect the transmission extension harness and the main harness leading to the transmission valve block. Look for rubbed insulation, pinched wires, or melted casing that could cause the solenoid's power wire to short against another high-voltage power source.

4. 4

   Test the Solenoid: Disconnect the 19th gear clutch solenoid. Use a multimeter to check the resistance across the solenoid terminals. If the resistance is out of spec (indicating an internal short), the solenoid is the culprit.

5. 5

   Check Connector Voltage: With the key ON (engine off), probe the harness-side connector for the solenoid to see if it is receiving constant high voltage when it shouldn't be.

1. 1

   Preparation

   Park the tractor on level ground, lower all implements, place all shift levers in neutral, block the wheels, and disconnect the battery.

2. 2

   Wiring Repair (If Applicable)

   If a short to power was found in the harness during diagnostics, splice and repair the damaged wires using weather-sealed connectors, or replace the damaged harness section.

3. 3

   Solenoid Replacement

   Locate the transmission valve block on the side of the transmission housing. Clean the area around the 19th gear clutch solenoid to prevent dirt from entering the hydraulic system. Disconnect the electrical connector, remove the retaining bolt/bracket, and pull the faulty solenoid valve out. Lubricate the O-rings on the new solenoid with clean transmission fluid and install it. Torque the retaining bolt to OEM spec and reconnect the harness.

4. 4

   Clear Codes

   Reconnect the battery. Enter the H-Menu and use the HC routine to clear stored error codes.

5. 5

   Transmission Calibration (Crucial Step)

   Whenever a PWM solenoid valve is replaced, the transmission must be recalibrated. Warm the transmission hydraulic fluid to operating temperature. Enter the H-Menu and navigate to H1 (Clutch and Synchronizer Calibration). Set the engine speed to 1200 ERPM. Follow the on-screen prompts, using the upshift button to engage the clutch packs. The controller will figure the mA required before a drop in engine RPM is measured. Proceed through all clutches until the "CAL" process is complete.