Case IH 141 – Engine Controller (ENG / ECM): Oil Pressure Sensor voltage is too low

The Engine Control Module (ECM) has detected that the signal voltage from the engine oil pressure sensor has fallen below the normal operating range. This condition is typically caused by an open circuit or a short to ground in the sensor wiring, or a complete failure of the sensor itself.

• MX Magnum
• STX Steiger
• TG Series tractors
• Steiger series tractors
• Puma series tractors
• Farmall series tractors
• JX series tractors
• Various Case IH combines and equipment with 8.3L, 9L, or 15L engines

1. 1

   Check for multiple active sensor codes to determine if there is a shared 5-volt supply or ground wire issue in the engine harness

2. 2

   Visually inspect the oil pressure sensor (located in the engine oil rifle/block) and its 3-pin connector for physical damage, corrosion, or pushed-back pins

3. 3

   Use a multimeter to verify the ECM is providing a 5-volt supply to the sensor and that the ground circuit is intact

4. 4

   Test the signal wire for continuity to the ECM (e.g., pin A33 on MX/TG models) and ensure it is not shorted to ground or open

1. 1

   Turn keyswitch OFF

   Turn the keyswitch to the OFF position.

2. 2

   Locate sensor

   Locate the engine oil pressure sensor on the engine block.

3. 3

   Disconnect connector

   Disconnect the 3-pin engine harness connector from the sensor.

4. 4

   Repair wiring

   If the diagnostic checks reveal a wiring issue (short to ground or open circuit), repair the damaged section of the engine harness or replace the connector plug.

5. 5

   Replace sensor

   If the wiring tests good, the sensor has failed internally. Remove the faulty oil pressure sensor and install the new OEM replacement part.

6. 6

   Reconnect harness

   Reconnect the engine harness to the sensor.

7. 7

   Validate repair

   To validate the repair, perform a key cycle, start the engine, and let it idle for 1 minute. The fault code status should change to INACTIVE.

8. 8

   Clear fault codes

   Use a recommended electronic service tool (such as Jaltest or Cummins INSITE) to issue a "Reset All Faults" command and clear the inactive code from the ECM memory.