Case IH t16 – PCU (Power Control Unit) or Engine Control Module: Shut-Off Signal, Shorted To High Source

The control module is detecting an unexpectedly high voltage on the circuit responsible for the fuel shut-off signal, typically indicating that the wiring is shorted to a power source (like the battery positive) or that the fuel shut-off solenoid has failed internally.

• MXM
• Case IH MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Case IH MX Series
• MX100
• MX110
• MX120
• MX135
• MX150
• MX170
• Case IH TG Series
• TM115-TM165

1. 1

   Inspect the Wiring Harness: Trace the wiring from the PCU to the fuel shut-off solenoid on the fuel injection pump. Look for rubbed, melted, or pinched wires that could be shorting the signal wire to a 12V power source.

2. 2

   Check the Connector: Disconnect the fuel shut-off solenoid and inspect the pins for corrosion, moisture, or damage.

3. 3

   Test the Solenoid: Use a multimeter to check the resistance of the fuel shut-off solenoid. An internal short in the electromagnet can cause a high voltage reading back to the PCU.

4. 4

   Check PCU Pins: Inspect the harness connection at the Power Control Unit for bent pins or water intrusion.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Locate the Solenoid

   Find the fuel shut-off solenoid, which is typically mounted directly to the rotary fuel injection pump.

3. 3

   Remove the Faulty Component

   Disconnect the electrical connector from the solenoid. Unthread/unbolt the old solenoid from the injection pump housing (on some earlier versions, you may need to remove a mounting bracket).

4. 4

   Install the New Solenoid

   Thread the new fuel shut-off solenoid into the injection pump. Ensure the proper thread pitch and mounting design match the old unit.

5. 5

   Reconnect Wiring

   Plug the electrical connector back into the new solenoid, ensuring it is clean and tight.

6. 6

   Test

   Reconnect the battery, turn the key to the ON position to verify the solenoid clicks open, and start the tractor. Turn the key off to ensure the engine shuts down cleanly. Clear the t16 fault code from the PCU.