Case IH 3012 – Engine Controller (ENG) / Engine ECU: Air Intake Temperature Sensor - (via CAN) No Signal

This code indicates that the engine control module is not receiving a valid signal from the air intake temperature sensor over the Controller Area Network (CAN) bus. The underlying condition is typically a null signal caused by a defective sensor, an open circuit, or a short circuit (either to ground or to an external power source).

• Magnum 235 - 340 (Series 4)
• Steiger
• Puma
• Case 580 Super N backhoes

1. 1

   Restart the machine's system to see if the problem reoccurs, as the system does not perform an initial CAN plausibility check for this specific fault.

2. 2

   Inspect the wiring harness leading to the air intake temperature sensor for chafed wires, broken connections, or melted insulation.

3. 3

   Disconnect the sensor and check the pins for corrosion, moisture, or pushed-back terminals.

4. 4

   Use a multimeter to check for an open circuit, a short circuit to ground, or a short circuit to an external voltage source (+V) on the sensor's signal and return wires.

1. 1

   Power down machine

   Power down the machine and turn off the battery disconnect switch.

2. 2

   Locate sensor

   Locate the Air Intake Temperature Sensor (often integrated as a Manifold Absolute Pressure/Temperature sensor) on the engine's air intake manifold.

3. 3

   Unplug connector

   Unplug the electrical connector from the sensor.

4. 4

   Repair wiring

   If the diagnostic circuit tests (above) reveal damaged wiring, repair the harness or replace the pigtail connector.

5. 5

   Remove defective sensor

   If the wiring tests good, the sensor itself is defective. Unbolt/unscrew the old sensor from the intake manifold.

6. 6

   Install new sensor

   Install the new OEM replacement sensor and torque to the manufacturer's specification.

7. 7

   Reconnect harness

   Reconnect the wiring harness.

8. 8

   Clear fault codes

   Connect an approved diagnostic Electronic Service Tool (EST) to clear the fault codes from the Engine ECU.

9. 9

   Verify repair

   Run the machine under normal operating conditions to verify the code does not return.