Case IH 2351 – Transmission Controller (TCU): 1F (1st Forward) clutch solenoid is shorted to a +12 volt power supply while the driver is commanded off

The transmission controller monitors the current draw from the clutch solenoid circuits; if it detects voltage on the circuit when the controller is not actively sending power to it, it logs this code. This typically points to a wiring harness that has rubbed through and shorted to a live power wire, or an internal short within the solenoid coil itself.

• Steiger T4B
• STX325
• STX350
• STX430
• STX450
• STX500
• Steiger 535
• Quadtrac 600

1. 1

   Locate the transmission controller underneath the fuse/relay panel in the cab and the 1F clutch solenoid on the transmission valve body.

2. 2

   Visually inspect the wiring harness between the transmission controller and the 1F clutch solenoid for pinched wires, melted insulation, or areas where it may be rubbing against the chassis and shorting to a +12V source.

3. 3

   Ensure the connectors are fully seated, not damaged, and that the pins are tight and free of corrosion.

4. 4

   Disconnect the 1F clutch solenoid connector (C029) and measure the resistance of the solenoid coil between cavity A and cavity B. Resistance should measure approximately: 9.4 to 11.4 ohms at 4°C (40°F), 9.9 to 12.1 ohms at 15°C (60°F), 10.3 to 12.7 ohms at 27°C (80°F), 10.8 to 13.2 ohms at 38°C (100°F), and 11.2 to 13.8 ohms at 49°C (120°F).

1. 1

   Resolve the Short

   If the solenoid resistance falls outside the specified ranges, the solenoid coil has failed internally and the 1F clutch solenoid must be replaced. If the solenoid tests within spec, use a multimeter to trace the short-to-power (+12V) in the wiring harness between connector C029 and the TCU. Repair or splice the damaged section of the wiring harness.

2. 2

   Reassemble

   Reconnect all electrical connectors, ensuring the pins are in the correct position and the fit is tight.

3. 3

   Clear Codes

   Turn the key on and use the Electronic Service Tool (EST) or the tractor's diagnostic display to clear the fault code.

4. 4

   Recalibrate

   Because a transmission clutch circuit was disrupted, perform a transmission clutch calibration procedure (accessed via the Trans Setup menu) to ensure the 1F clutch engagement point is properly learned by the TCU.