Case IH 2813 – Transmission Control Unit (TCU): Transmission oil temperature Sensor Short to Ground

The control module is receiving a voltage signal from the transmission oil temperature sensor that is below the minimum acceptable threshold. This typically happens when the sensor's internal circuitry fails and shorts to ground, or when the wiring harness connecting the sensor to the module has rubbed through its insulation and is touching the machine's chassis (ground).

• Magnum
• Steiger T4B
• Case IH Magnum Series (e.g., Magnum 210, 235–340 Series 4)
• Case IH Steiger Series
• Case IH MX Magnum and TG Series

1. 1

   Visually inspect the wiring harness leading from the Transmission Control Unit to the transmission oil temperature sensor for pinched wires, melted insulation, or rubbing against the chassis.

2. 2

   Disconnect the sensor and inspect the electrical connector pins for moisture, corrosion, or damage.

3. 3

   With the sensor disconnected, turn the key on and check if the active fault code changes to 2812 (Open Circuit). If it changes, the sensor is internally shorted. If 2813 remains, the short is in the wiring harness.

4. 4

   Measure the resistance across the sensor's terminals with a multimeter. A reading near zero ohms indicates the sensor has failed.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the transmission oil temperature sensor on the transmission housing (refer to your specific model's service manual for the exact port location).

3. 3

   Harness Repair (If Applicable)

   If the diagnostic checks revealed a wiring short, splice and repair the damaged section of the harness using heat-shrink connectors, then wrap it in protective loom.

4. 4

   Sensor Replacement (If Applicable)

   Disconnect the electrical pigtail from the sensor. Place a clean catch pan under the sensor area, as a small amount of transmission fluid may leak out. Unthread the faulty sensor from the transmission housing using a wrench. Thread the new OEM sensor into the port and tighten to the manufacturer's torque specification.

5. 5

   Reassembly

   Reconnect the electrical connector, ensuring the locking tab clicks into place. Reconnect the battery.

6. 6

   Clear Codes

   Turn the ignition on. Use the tractor's display panel or an Electronic Service Tool (EST) to clear the inactive fault codes. Start the machine and verify that the transmission temperature reads correctly and Code 2813 does not return.