Case IH 2156 (519171.03) - DEC – Transmission/Drivetrain Controller: ESPTO ACTUATOR POS SIGNAL - short to high voltage

The signal wire for the position sensor (Electronic Shift PTO / ESPTO Actuator Position Signal) is experiencing a short to high voltage. The control module is receiving a voltage reading from the sensor circuit that is above the normal operating range, typically caused by the signal wire shorting directly to a 12V power source or a 5V reference wire (VCC), or an internal failure of the sensor itself.

• MAXXUM T4E
• Case IH Puma series (165, 180, 195, 210, 225 CVX)
• Case IH Farmall Pro series (95U, 105U, 115U)

1. 1

   Access Live Diagnostics: Enter the tractor's diagnostic display mode. You can view active codes by putting the system into 'Live' error code mode rather than 'ECR' (error code reduction) mode to see all critical and non-critical faults.

2. 2

   Wiring Harness Inspection: Refer to the wiring harness overview (Section A.30.A in the Case IH manual) to identify the specific wiring color codes for the ESPTO actuator position sensor.

3. 3

   Voltage Check: Test the sensor's signal circuit with a multimeter to verify if it is shorted to a power source (12V or 5V Vref).

1. 1

   Safety First

   Stop the engine and ensure that all pressure is relieved from the hydraulic circuits before removing any caps, covers, or valves. Never carry out maintenance operations when the engine is running.

2. 2

   Locate the Sensor

   Locate the ESPTO actuator position sensor (or Synchro position sensor) on the transmission/PTO housing.

3. 3

   Inspect Wiring

   Carefully inspect the wiring harness leading to the sensor. Look for damaged, melted, or frayed wires that could be bridging the signal wire to a voltage supply wire.

4. 4

   Repair or Replace

   If a wiring short is found, repair the harness. If the wiring tests good, the sensor has failed internally and must be replaced.

5. 5

   Clear Codes

   After replacing the sensor or repairing the wire, cycle the key. Depress and hold the navigation 'up' or 'down' key on the diagnostic display to store/confirm selections and clear the codes.