Case IH 2447 (160.02) - DEC – ECU (Electronic Control Unit) or Transmission Control Module: Hydro Out Speed Sensor - Signal wire shortcut to GND

The ECU detects noise on the wheel/transmission speed input, or cannot receive wheel speed data either via the CAN bus or a direct line for more than 3 seconds. This lack of valid signal is caused by the sensor's signal wire being shorted directly to ground, preventing the transmission output speed from being read.

• VESTRUM CVX
• Magnum 220 Tier 4B CVT (NA)
• Puma 165, 180, 195, 210, and 225 CVX
• CR9070
• Axial-Flow series

1. 1

   Verify if the ECU is receiving any wheel speed data via the CAN bus or direct line. The fault triggers if data is lost for more than 3 seconds.

2. 2

   Inspect the chassis wire harness leading to the Hydro Out Ring Speed Sensor (specifically connector X-1283) for chafing, melting, or pinching that would cause the signal wire to short to ground.

3. 3

   Check if the hydro-in or hydro-out sensor is physically damaged.

4. 4

   Ensure there is no low pressure on the hydraulic circuit or an underlying mechanical problem in the transmission causing erratic speed readings.

1. 1

   Access diagnostics

   Connect the special diagnostic tool (e.g., tool 380000843) to the diagnostic connector and turn the key start switch ON to access the controller menu (such as the 'H Menu' on Puma/Magnum models) to verify the active DTC.

2. 2

   Locate the sensor

   Locate the Hydro Out Ring Speed Sensor / Trans Output Speed Sensor on the transmission housing. In Case IH wiring schematics, this is identified at connector X-1283.

3. 3

   Inspect and repair wiring

   Disconnect the 3-way electrical connector. Test the signal wire for continuity to ground. If a short is found, repair the damaged section of the chassis wire harness or replace the connector terminals.

4. 4

   Replace the sensor

   If the wiring tests good but the sensor is internally shorted, remove and replace the Hydro Out Speed Sensor.

5. 5

   Clear codes

   Use the diagnostic equipment to clear the DTCs from the ECU memory.

6. 6

   Recalibrate transmission

   After repairing transmission sensors, perform the Full Power Shift Transmission (FPS) calibration or Electronic Draft Control calibration as required by the specific tractor model to ensure proper shifting and speed reading.