Case IH 566-04 - DEC – DEC: Rear differential lock control solenoid electrical circuit fault voltage below normal

The electrical circuit responsible for operating the rear differential lock control solenoid is experiencing a voltage below normal condition, which typically points to a short to ground, high resistance in the wiring harness, or a failing solenoid coil.

• MAGNUM AFS Connect
• Magnum MX Series
• STX Series
• Farmall Pro EP Series
• Maxxum Series
• 5120
• 5130

1. 1

   Inspect the wiring harness connecting the DEC module to the rear differential lock control solenoid for chafing, shorts to ground, or damaged connectors.

2. 2

   Test the solenoid coil resistance using a digital multimeter to ensure it is within OEM specifications.

3. 3

   Verify the DEC module is outputting the correct voltage to the solenoid circuit.

1. 1

   Locate solenoid

   Locate the rear differential lock control solenoid on the transmission/rear axle housing.

2. 2

   Disconnect harness

   Disconnect the electrical harness from the solenoid.

3. 3

   Remove solenoid

   Remove the retaining hardware and extract the faulty solenoid valve.

4. 4

   Install new solenoid

   Install the new solenoid with new O-rings (lubricated with clean hydraulic/transmission fluid).

5. 5

   Reconnect and clear codes

   Reconnect the electrical harness and clear the fault codes from the DEC module using the Case IH Electronic Service Tool (EST).