Case IH 5913-04 - DEC – DEC: Transmission Oil Temperature Sump - Voltage below normal, or shorted to low source

The controller is reading a voltage drop on the transmission oil temperature sensor's signal circuit that is below the acceptable operating threshold. This is almost always caused by the sensor's signal wire being shorted directly to ground, a failed sensor that is internally shorted, or a failure in the 5V reference supply to the sensor.

• MAGNUM AFS Connect
• Magnum Series: 180, 190, 200, 210, 220, 225, 240
• Maxxum Series: 110, 115, 120, 125, 130, 135, 145
• Puma Series: 130, 145, 150, 160, 165, 170, 180, 185, 195, 200, 210, 215, 220, 225, 230, 240
• Older MX Series: MX80C, MX90C, MX100, MX110, MX120, MX135

1. 1

   Perform a visual harness inspection from the transmission sump temperature sensor back to the DEC/TCU, looking for chafing, bare wires, or pinched sections shorting to ground.

2. 2

   Disconnect the sensor and inspect the connector pins for corrosion, moisture, or pushed-back terminals.

3. 3

   With the key ON and sensor disconnected, measure voltage at the harness connector to verify the 5V reference supply (0V indicates a short to ground before the connector or module failure).

4. 4

   Measure the resistance across the sensor's terminals (a reading near zero ohms indicates an internal short and requires replacement).

1. 1

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

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

2. 2

   Disconnect the negative battery cable to protect the electronic controllers from voltage spikes.

   Disconnect the negative battery cable to protect the electronic controllers from voltage spikes.

3. 3

   Locate the transmission oil temperature sensor, which is threaded into the transmission sump or lower valve block.

   Locate the transmission oil temperature sensor, which is threaded into the transmission sump or lower valve block.

4. 4

   Clean the area around the sensor thoroughly to prevent dirt or debris from entering the transmission fluid.

   Clean the area around the sensor thoroughly to prevent dirt or debris from entering the transmission fluid.

5. 5

   Place a clean drain pan under the sensor location, as a small amount of transmission fluid will escape when the sensor is removed.

   Place a clean drain pan under the sensor location, as a small amount of transmission fluid will escape when the sensor is removed.

6. 6

   Disconnect the electrical connector from the sensor.

   Disconnect the electrical connector from the sensor.

7. 7

   Unscrew the faulty sensor.

   Unscrew the faulty sensor.

8. 8

   Apply a transmission-safe thread sealant to the new sensor (if it does not come pre-applied) and quickly thread it into the sump to minimize fluid loss. Tighten to OEM specifications.

   Apply a transmission-safe thread sealant to the new sensor (if it does not come pre-applied) and quickly thread it into the sump to minimize fluid loss. Tighten to OEM specifications.

9. 9

   Reconnect the electrical harness, ensuring the weather-pack seal is intact and the lock clicks.

   Reconnect the electrical harness, ensuring the weather-pack seal is intact and the lock clicks.

10. 10

    Reconnect the battery, start the tractor, and let the transmission warm up.

    Reconnect the battery, start the tractor, and let the transmission warm up.

11. 11

    Clear the fault codes via the cab monitor or a diagnostic tool and verify that 5913-04 does not return. Top off the transmission fluid if necessary.

    Clear the fault codes via the cab monitor or a diagnostic tool and verify that 5913-04 does not return. Top off the transmission fluid if necessary.