Case IH 735-04 - DEC – DEC (Drivetrain Electronic Control): Transmission Range Clutch C2 Solenoid Voltage Below Normal, or Shorted to Low Source

The transmission controller has detected that the electrical circuit for the C2 clutch solenoid has dropped below the normal operating voltage range. This typically indicates a short circuit to ground (chassis) or a severely degraded connection on the power supply side of the solenoid circuit.

• MAGNUM AFS Connect
• Case IH Magnum
• Case IH Steiger
• Case IH Puma
• Case IH Maxxum

1. 1

   Inspect the transmission wiring harness routing from the DEC module to the transmission control valve block for chafed wire insulation, melted wires, or pinch points.

2. 2

   Disconnect the C2 clutch solenoid electrical connector and inspect the pins for corrosion, moisture ingress, or pushed-back terminals.

3. 3

   Using a multimeter, measure continuity between the C2 solenoid power supply wire and the tractor chassis ground to check for a short to ground.

4. 4

   Measure the resistance across the two pins of the C2 clutch solenoid. A reading of 0 ohms indicates an internal short (normal resistance is typically 5.3 to 10 ohms).

1. 1

   Prepare tractor for service

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the negative battery cable.

2. 2

   Locate valve block

   Locate the transmission control valve block (usually located on the right-hand side of the transmission housing).

3. 3

   Identify solenoid

   Identify the C2 clutch solenoid on the valve block (refer to the specific tractor model's hydraulic/transmission schematic for exact placement).

4. 4

   Disconnect connector

   Disconnect the electrical connector from the C2 solenoid.

5. 5

   Repair wiring

   If the diagnostic tests pointed to a wiring issue, splice and repair the damaged section of the harness or replace the connector pigtail.

6. 6

   Remove retaining bolt

   If the solenoid is internally shorted, remove the retaining bolt and bracket holding the C2 solenoid in the valve body.

7. 7

   Remove solenoid

   Carefully pull the solenoid straight out of the bore. Have a drain pan ready to catch residual transmission fluid.

8. 8

   Lubricate O-rings

   Lubricate the O-rings on the new C2 clutch solenoid with clean OEM transmission fluid.

9. 9

   Install new solenoid

   Insert the new solenoid into the valve block bore, ensuring it seats fully. Reinstall the retaining bracket and torque the bolt to OEM specifications.

10. 10

    Reconnect components

    Reconnect the electrical connector and the battery.

11. 11

    Calibrate transmission

    Start the tractor, clear the inactive fault codes from the DEC, and perform a transmission clutch calibration procedure (often required when replacing a PWM clutch solenoid).