Case IH 3024 (F-108-03) - ECU – Engine Control Module (ECM) / Engine Control Unit (ECU): ECU internal failure - Ambient air pressure sensor voltage is higher than expected

The control module is receiving a voltage signal from the ambient (atmospheric) air pressure sensor that exceeds the maximum expected threshold. This typically indicates a short circuit to a power source, an open ground circuit, a failed sensor, or an internal hardware failure within the control unit itself.

• VESTRUM CVX
• Case IH Farmall 40, 45, and 50 Tractors (with Cab and CVT Transmission)
• Case IH 9900 series
• Various Case IH and New Holland tractors utilizing AGCO Power engines or standard CNH engine controllers

1. 1

   Verify sensor location to determine if the ambient air pressure sensor is a standalone component on the intake manifold or integrated internally into the ECM.

2. 2

   If the sensor is external (wiring cause), inspect the sensor's wiring harness for a short to battery voltage or an open ground circuit. Inspect the connector pins for corrosion, moisture, or damage.

3. 3

   If the sensor is external (sensor failure cause), use a multimeter to measure the signal voltage coming from the sensor to the ECM. If the voltage is pinned high (e.g., 5V on a 5V reference circuit), the sensor is likely shorted internally or the ground is dropped.

4. 4

   If the wiring is intact and the sensor is functioning, or if the sensor is internal to the ECM (internal ECM failure cause), perform an ECM self-check to verify internal hardware failure.

1. 1

   Disconnect power

   Turn off the machine and disconnect the battery before servicing ECM connections or sensors.

2. 2

   Repair wiring

   If a short to power or open ground was found during diagnostics (wiring cause), repair the damaged section of the harness or replace the connector pigtail.

3. 3

   Replace the sensor

   If the external ambient air pressure sensor is faulty (sensor failure cause), remove the mounting hardware, unplug the electrical connector, and install the new sensor.

4. 4

   Replace the ECM

   If the sensor is integrated into the ECM or the ECM's internal circuitry has failed (internal ECM failure cause), the ECM must be replaced.

5. 5

   Restore parameters

   If the ECM is replaced, use the appropriate CNH service tool to restore self-learning parameters and flash the correct software for the machine.

6. 6

   Clear codes

   Reconnect the battery, cycle the key, and use a diagnostic tool to clear the inactive 3024 fault code.