Case IH 15 – Transmission ECM: C1_SW_LO_DIS_ERR

This is a transmission fault indicating a disabling error with the LO push button (Clutch 1 Switch Low) located on the gear shift lever. The transmission controller has detected an anomalous electrical condition in this switch's circuit (short to ground, short to 5V/12V, or open circuit), triggering a CP/SL Dis (Clutch Pedal / Shuttle Lever Disabled) correction effect that critically limits or disables the transmission gears for safety.

• JXC
• JXU75
• JXU85
• JXU95
• JXU105
• JXU115
• Farmall
• TN60A
• TN70A
• TN75A
• TN85A
• TN95A

1. 1

   Perform a live switch test using the diagnostic H-Menu (Menu H5) to see if the Transmission ECM registers the LO push button input

2. 2

   Check live error codes in Menu HD to determine if the error is currently active or just stored

3. 3

   Physically inspect the LO push button on the gear shift lever for sticking, dirt ingress, or mechanical collapse

4. 4

   Probe the wiring harness between the gear shift lever and the Transmission ECM for an open circuit, short to ground, or short to the 5V/12V sensor supply

1. 1

   Disconnect Power

   Park the tractor safely, turn the starter key to the OFF position, and disconnect the battery negative lead to prevent electrical damage.

2. 2

   Access the Switch

   If the H5 switch test failed, carefully disassemble the main gear shift lever knob to access the HI/LO push button microswitches.

3. 3

   Replace or Repair

   If the LO switch is mechanically broken or internally shorted, replace the switch or the entire gear shift knob assembly. If the switch tests fine with a multimeter, trace the wiring harness down the lever and under the cab floor to the Transmission ECM, repairing any chafed or broken wires.

4. 4

   Reassemble and Reconnect

   Reassemble the shift lever and reconnect the battery negative lead.

5. 5

   Clear Codes

   Enter the diagnostic H-Menu and select Menu HC to clear the stored error codes.

6. 6

   Re-enable Transmission

   Reset the system and re-enable the gears by cycling the Power Shuttle (SL) FNR lever and/or fully depressing the Clutch Pedal (CP).