Case IH 3025 (DTC 24C4) - ECU – Engine Control Unit (ECU) / A-095: ECU internal failure - Ambient pressure sensor voltage is lower than expected.

The Engine Control Unit (ECU) has detected an abnormally low voltage (less than 190.00 mV for greater than 800 milliseconds) from the internal ambient (atmospheric) pressure sensor.

• MAXXUM T4E
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Puma series
• Magnum series
• Austoft Sugar Cane Harvesters (8800, 9900)
• Case 580 Super N Backhoes

1. 1

   Check for external power supplies: Verify that the machine's battery has not been connected to an external power supply (jump-starter, booster pack, or external charger). If connected, disconnect it, clear the codes, and test for normal operation.

2. 2

   Verify with EST: Connect the Case IH Electronic Service Tool (EST) to verify if the fault is currently active.

3. 3

   Cross-test controllers: If available, temporarily swap the ECU with another known-good controller (e.g., an EEM3 controller). If the fault is no longer active, the original ECU is confirmed defective.

1. 1

   Turn off the machine and disconnect the battery

   Turn off the machine and disconnect the battery to prevent electrical arcing.

2. 2

   Locate the Engine Control Unit

   Locate the Engine Control Unit (A-095) on the machine.

3. 3

   Disconnect the main wiring harness connectors

   Disconnect the main wiring harness connectors from the ECU.

4. 4

   Unbolt and remove the defective ECU

   Unbolt and remove the defective ECU.

5. 5

   Install the replacement ECU

   Install the replacement ECU and reconnect the wiring harnesses.

6. 6

   Reconnect the battery

   Reconnect the battery.

7. 7

   Flash and configure the new ECU

   Calibration/Programming: The new ECU must be flashed and configured to the specific machine using the Case IH Electronic Service Tool (EST).