Case IH 2657 – ZTC: ZTC - Range clutch K1 is shorted to power

The transmission controller has detected a short circuit to battery voltage (power) on the electrical circuit controlling the K1 Range Clutch. When this circuit is shorted to power, the solenoid may remain energized unintentionally, or the controller will disable the circuit to protect the system, resulting in a loss of specific gears or a transmission default/limp mode.

• Steiger T4B
• Steiger AFS Connect
• Maxxum
• Puma
• Farmall U Pro 95U
• Farmall U Pro 105U
• Farmall U Pro 115U
• Farmlift 635
• Farmlift 742
• Motor Grader 845B
• Motor Grader 856C

1. 1

   Visually inspect the wiring harness running from the ZTC to the transmission valve block for rubbed-through insulation where the K1 solenoid wire might be touching a 12V power source

2. 2

   Disconnect the harness at the ZTC and at the K1 clutch solenoid, then use a multimeter to check for voltage on the K1 signal wire with the key ON (voltage indicates a harness short to power)

3. 3

   Measure the resistance across the pins of the K1 clutch solenoid and compare to OEM specifications to check for an internal short in the coil

4. 4

   Check the ZTC controller fuses (e.g., the 5A switched power fuse) to ensure the short hasn't caused a blown fuse

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery ground cable to prevent electrical spikes.

2. 2

   Access the Valve Block

   Locate the transmission control valve block on the side or top of the transmission housing. Identify the K1 clutch proportional solenoid valve.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a short in the harness, splice and heat-shrink the damaged wire, or replace the transmission sub-harness entirely.

4. 4

   Replace Solenoid

   If the K1 solenoid coil is internally shorted, remove the retaining bolt/clip holding the solenoid to the valve block. Extract the solenoid, lubricate the O-rings on the new solenoid with clean transmission fluid, and install it. Torque the retaining fastener to OEM spec.

5. 5

   Reassemble and Calibrate

   Reconnect the wiring harness and battery. Clear the inactive fault codes from the ZTC.

6. 6

   Clutch Calibration

   Perform a Transmission Clutch Fill Calibration via the tractor's display or an EST diagnostic tool so the ZTC can learn the fill time of the K1 clutch.