Case IH 736-06 - DEC – Transmission Control Unit (TCU): Transmission Range Clutch C3 Solenoid - Current above normal or shorted to ground

The electrical current in the circuit is above normal or the circuit is closed/shorted to ground. This condition occurs when the ECU detects that the energize circuit of the solenoid is shorted to the +battery circuit, shorted to ground, or the solenoid coil itself has failed internally, causing an excessive current draw.

• MAGNUM AFS Connect
• Magnum series
• MX210
• 7140

1. 1

   Turn the key start switch and the battery disconnect switch to the OFF position.

2. 2

   Disconnect the machine harness connectors from the C3 clutch solenoid and the ECU.

3. 3

   Inspect the harness connectors visually. Clean the harness connector contacts and check the wires for damage to the insulation caused by excessive heat, battery acid, or chafing.

4. 4

   Perform a 10 lb (45 N) pull test on each of the wires associated with the solenoid circuit to ensure pins are seated tightly in their connectors.

5. 5

   Measure the resistance of the circuit. If the resistance measurement is low (not greater than 5000 ohms when checking for a short to ground or battery), there is a short in the machine harness between the ECU and the solenoid.

6. 6

   If a diagnostic service tool is available, perform a 'Wiggle Test' on the wiring harness to detect intermittent shorts or open circuits.

1. 1

   Harness Repair

   If the multimeter tests in the diagnostic phase reveal a short in the wiring harness (resistance < 5000 ohms), repair or replace the damaged section of the machine harness.

2. 2

   Solenoid Replacement

   If the wiring harness tests normal (no shorts detected), the C3 clutch solenoid itself has likely failed.

3. 3

   Locate valve block

   Locate the transmission control valve block on the transmission housing.

4. 4

   Disconnect connector

   Disconnect the electrical connector from the C3 clutch solenoid.

5. 5

   Remove solenoid

   Remove the retaining hardware holding the solenoid in the valve body and extract the faulty C3 clutch solenoid.

6. 6

   Install new solenoid

   Install the new solenoid, ensuring any O-rings are properly seated and lubricated with clean transmission fluid.

7. 7

   Reconnect harness

   Reconnect all harness connectors, making sure that the clips for each connector are fastened completely.

8. 8

   Verify repair

   Turn the disconnect switch and the key start switch to the ON position, operate the machine, and verify that the diagnostic trouble code is no longer active.