Case IH 736-05 - DEC – DEC: Transmission Range Clutch C3 Solenoid - Current below normal or open circuit

The transmission controller is attempting to energize the C3 clutch solenoid, but it detects that the electrical current draw is below the normal operating threshold. This indicates an open circuit, which is typically caused by a disconnected plug, a broken wire in the harness, or a burned-out (open) solenoid coil.

• MAGNUM AFS Connect
• MX210
• MX230
• MX255
• MX285
• Magnum 215
• Magnum 235
• Magnum 245
• Magnum 260
• Magnum 275
• Magnum 290
• Magnum 305
• Magnum 315
• Magnum 335
• Magnum 340
• Magnum 370

1. 1

   Visual Inspection: Locate the C3 clutch solenoid (Connector No. 32) on the transmission control valve. Inspect the wiring harness, connector, and pins for corrosion, moisture, or backed-out terminals.

2. 2

   Coil Resistance Test: Disconnect the machine harness from the C3 solenoid. Use a digital multimeter to measure the resistance across the solenoid's pins. If the multimeter reads 'OL' (open loop) or infinite resistance, the solenoid coil has failed internally and must be replaced.

3. 3

   Harness Jumper Test: To rule out a wiring harness or DEC controller failure, place a jumper wire across the two contacts on the machine harness side of the connector. Turn the key ON and observe the active fault codes. If the code changes to 736-06 (Short Circuit), the wiring harness and DEC are functioning properly. If the code remains 736-05, there is a broken wire between the DEC and the solenoid connector, or the DEC itself has a faulty driver.

1. 1

   Park the tractor on a level surface, engage the park brake, and turn off the engine.

2. 2

   Locate the transmission control valve assembly

   which is mounted on the pressure regulator valve on the right-hand side of the transmission housing.

3. 3

   Identify the C3 clutch solenoid

   refer to the transmission solenoid location diagram; look for Connector No. 32.

4. 4

   Disconnect the electrical connector from the C3 solenoid.

5. 5

   Thoroughly clean the area around the solenoid base

   to prevent dirt and debris from entering the transmission valve body.

6. 6

   Remove the retaining hardware securing the solenoid to the valve body.

7. 7

   Carefully pull the faulty C3 clutch solenoid out of the bore.

8. 8

   Lubricate the O-rings/seals on the new solenoid with clean transmission fluid.

9. 9

   Insert the new solenoid into the valve body and tighten the retaining hardware to the OEM torque specification.

10. 10

    Reconnect the electrical harness connector.

11. 11

    Turn the key ON and clear the fault codes

    using the tractor's diagnostic menu or a service tool.

12. 12

    Start the tractor and perform a transmission clutch calibration procedure

    to ensure the DEC adapts to the new solenoid's flow characteristics.