Case IH 13044 – INST or INST2: Incorrect Inst controller on tractor or differential lock relay coil current is too high.

The controller has sensed an excessive current draw (typically greater than 500 milliamps) on the relay coil circuit. This indicates that the differential lock relay coil is internally shorted, is beginning to fail, or there is a short circuit in the wiring harness.

• STX Steiger
• Magnum
• MX/TG Series
• Steiger
• Quadtrac
• Puma
• mechanical engine tractors

1. 1

   Clear the fault code, turn the key switch to OFF, then back to ON. Note if the code returns immediately or only after the tractor warms up (temperature sensitivity indicates a failing relay).

2. 2

   Check the transmission controller ground path. Verify it removes the ground at 18.5 KPH (11.5 MPH) and closes it when speed drops under 17.7 KPH (11 MPH).

3. 3

   Remove the differential lock relay and test the coil for an internal short circuit.

4. 4

   Check the wiring harness between the Instrument Controller (INST2), the transmission controller, and the differential lock relay for shorts to ground or power.

5. 5

   Verify that the instrumentation controller configuration matches the specific tractor model.

1. 1

   Locate the Relay

   Locate the differential lock relay on the tractor's relay mounting plate or main fuse/relay panel (location varies slightly by cab configuration, but is often grouped with the front/rear differential lock switchover valves or PTO relays).

2. 2

   Inspect the Socket

   Remove the relay and inspect the terminal socket for melted plastic, corrosion, or damaged pins that could cause a short.

3. 3

   Test/Replace the Relay

   Test the relay coil resistance with a multimeter. If the resistance is out of specification (causing the >500 mA current draw) or if the relay is heavily temperature sensitive, replace the differential lock relay.

4. 4

   Repair the Wiring Harness

   If the relay tests good, use a multimeter to trace the wiring from the relay socket back to the Instrument Cluster (INST2) and the Transmission Controller. Repair any chafed wires or shorts found in the harness.

5. 5

   Reconfigure the Controller

   If the wiring and relay are perfectly intact, connect the Case IH Electronic Service Tool (EST). Verify the Instrumentation Controller configuration. If the configuration is corrupted or incorrect for the tractor model, reconfigure or re-flash the INST2 module.

6. 6

   Final Testing

   Clear the fault codes. Test drive the tractor, accelerating past 11.5 MPH and decelerating below 11 MPH to ensure the transmission controller properly cycles the ground path and the differential lock engages/disengages without triggering the code.