Case IH F69 – Transmission Controller (TCU): Shuttle Lever Reverse Switch Input Voltage High

The control module is receiving a voltage signal from the reverse switch on the Forward/Neutral/Reverse (FNR) shuttle lever that is higher than the expected normal range. This typically indicates that the reverse switch input circuit is shorted to a +12V power source or a 5V reference line, or that the physical switch inside the lever assembly is stuck in a closed/faulty position.

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

1. 1

   Cycle the shuttle lever back and forth between forward, neutral, and reverse several times with the tractor off to free up a potentially stuck micro-switch.

2. 2

   Inspect the wiring harness running down the steering column from the shuttle lever to the transmission controller for rubbed wires, pinched harnesses, or mud/debris causing a short to power.

3. 3

   Using a multimeter, back-probe the reverse switch input at the shuttle lever connector to verify if the circuit is shorted to +12V or the 5V reference line.

4. 4

   Check the forward/reverse relays in the right-hand dash and the solenoids on the side of the transmission to ensure they are clicking properly and haven't backed out of their sockets.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent any electrical shorts during the repair.

2. 2

   Remove the Steering Wheel

   Depending on your exact cab configuration, you may need to remove the center cap and the steering wheel nut to pull the steering wheel off for clearance.

3. 3

   Remove Steering Column Shrouds

   Take off the plastic steering column covers to expose the base of the gear selector/shuttle lever assembly.

4. 4

   Disconnect the Switch

   Locate the wiring harness pigtail coming from the shuttle lever and disconnect it from the main cab harness.

5. 5

   Remove the Assembly

   Unbolt the faulty gear selector/shuttle lever assembly from its mounting bracket on the steering column.

6. 6

   Install the New Part

   Mount the new shuttle lever switch assembly, secure the bolts, and plug the connector into the wiring harness.

7. 7

   Reassembly

   Reinstall the steering column shrouds and the steering wheel.

8. 8

   Test

   Reconnect the battery, turn the key on, and verify that the F69 code has cleared. Test forward and reverse engagement.