Case IH 3624 – Engine Control Unit (ECU): Crank case pressure sensor - Voltage above upper limit

The Engine Control Unit (ECU) has detected a fault associated with the crankcase pressure sensor. Specifically, the signal voltage returning to the ECU is greater than 4.8 V. This indicates that the crankcase pressure signal is out of range of the upper threshold limit, which is typically caused by a faulty sensor or a wiring issue (such as a short to power or an open circuit).

• Case IH Farmall series tractors
• Case IH Maxxum series tractors
• Case IH Combines (5140, 6140, 7140, 7240, 8240, 9240)

1. 1

   Use the Electronic Service Tool to verify the active fault code

2. 2

   Inspect the wiring harness leading to the crankcase pressure sensor for physical damage, chafing, or corrosion

3. 3

   Check the wiring for a short to a power source or a broken ground/signal wire causing an open circuit (voltage reading above 4.8V)

4. 4

   Ensure the crankcase pressure sensor is mounted properly and securely in its correct location

1. 1

   Locate the crankcase pressure sensor on the engine block.

2. 2

   Disconnect the 3-pin electrical connector from the sensor.

3. 3

   Inspect the connector pins for corrosion or bent terminals. Clean if necessary.

4. 4

   If the wiring harness is in good condition and the sensor is mounted correctly, the failure mode is a faulty sensor.

5. 5

   Unbolt/unscrew the defective crankcase pressure sensor from the engine.

6. 6

   Install the new OEM replacement sensor.

7. 7

   Reconnect the electrical harness.

8. 8

   Clear the fault codes using the Electronic Service Tool and run the engine to verify that the 3624 code does not return.