Case IH 3629 – Engine Control Unit (ECU): Plausibility check for Crank Case pressure sensor failed

The Engine Control Unit (ECU) calculates an expected value for the crankcase pressure based on the engine's current operating point. If the reading provided by the crankcase pressure sensor falls outside of this expected calculated range, the plausibility check fails and the code is triggered.

• Case IH Steiger Tractors (350 to 600 hp)
• Case IH Luxxum Tractors (100, 110, 120)
• Case IH Combines (5140, 6140, 7140, 7240, 8240, 9240)
• Case IH Magnum Tractors
• Case IH Maxxum Tractors

1. 1

   Visual Inspection of Mounting: Check the physical installation of the crankcase pressure sensor on the engine block.

2. 2

   Wiring and Connector Check: Ensure the sensor's 3-pin connector is securely fastened and free of corrosion, moisture, or damaged wires that could skew the electrical signal to the ECU.

3. 3

   Key-On Test: Use an Electronic Service Tool to monitor the crankcase pressure sensor value at 'Key On, Engine Off' to check for implausible values indicating a failed sensor or dead short.

1. 1

   Locate

   Locate the crankcase pressure sensor on the engine block.

2. 2

   Inspect

   Inspect the mounting. If the sensor is loose or improperly seated, remount it correctly, clear the fault code, and run the engine to see if the code returns.

3. 3

   Diagnose

   If the sensor is mounted properly and the wiring harness tests good, the sensor itself has failed internally.

4. 4

   Disconnect

   Disconnect the electrical harness from the sensor.

5. 5

   Remove

   Unbolt/remove the defective crankcase pressure sensor.

6. 6

   Install

   Install the new OEM crankcase pressure sensor and torque to factory specifications.

7. 7

   Reconnect

   Reconnect the wiring harness.

8. 8

   Verify

   Clear the fault codes using an Electronic Service Tool and run the machine to verify the repair.