Case IH 3030 (DTC 29D3) - ECU – Engine Control Unit (ECU): Oil pressure sensor voltage is lower than expected

The control module detects a voltage of less than 200 mV for a period greater than 500 ms in the pressure signal circuit of the oil pressure sensor (B-014).

• MAXXUM T4E
• Puma series
• Magnum series
• MX210
• MX230
• MX255
• MX285
• Maxxum series
• Farmall series
• 240 Series Axial-Flow Combines
• 7230
• 8230
• 9230

1. 1

   Check for other codes to verify if they point to a broader electrical issue.

2. 2

   Check power supply to ensure the tractor's battery power supply has not been connected to an external power supply; if connected, disconnect it and test.

3. 3

   Visually inspect the relevant harnesses and connectors between the oil pressure sensor (B-014) and the ECU (A-095) for damage, bent or dislocated pins, corroded terminals, or broken wires.

4. 4

   Perform a wiggle test by flexing the involved harnesses to reveal any intermittent wiring issues or shorts to ground.

5. 5

   Verify that all connectors are fully installed and seated properly.

1. 1

   Perform diagnostic wiring and voltage checks

   Repair any damaged wiring or corroded pins in the B-014 sensor circuit.

2. 2

   Replace the oil pressure sensor (B-014)

   If the wiring harness and ECU output are intact but the voltage remains below the 200 mV threshold, the oil pressure sensor (B-014) has likely suffered an internal failure and must be replaced.

3. 3

   Remove the faulty sensor

   Locate the engine oil pressure sensor, disconnect the 2-terminal harness, and unthread the faulty sensor.

4. 4

   Install the new sensor

   Install the new OEM replacement sensor and reconnect the harness.

5. 5

   Verify the repair

   Use the Case IH Electronic Service Tool (EST) to verify that fault code 3030 (DTC 29D3) has been resolved. If resolved, return the machine to service.

6. 6

   Check and re-flash the ECU

   If the code has not been resolved after wiring repairs and sensor replacement, check the A-095 ECU for the appropriate software and re-flash the module if necessary.