Case IH 13040 – Instrumentation Controller (INST or INST2): Air to Air Intake Temperature sensor is failed in the Engine Controller

The engine control module is receiving an invalid, missing, or out-of-range signal from the sensor that monitors the temperature of the air coming from the charge air cooler (air-to-air cooler) into the intake manifold.

• MX Magnum
• STX Steiger
• Case IH MX Magnum Series
• Case IH TG Series
• Case IH Puma Series
• Case IH Steiger Series

1. 1

   Test the air-to-air intake temperature sensor resistance using a multimeter to verify it falls within the OEM specified range

2. 2

   Inspect the wiring harness between the sensor, engine controller, and instrumentation controller for open circuits, chafing, or shorts to ground

3. 3

   Verify the instrumentation controller has a good power and ground supply, as a failure here can erroneously trigger sensor faults

1. 1

   Locate sensor

   Turn off the machine and locate the air-to-air intake temperature sensor, typically mounted on the intake manifold or the piping exiting the charge air cooler.

2. 2

   Disconnect sensor

   Disconnect the electrical connector from the sensor.

3. 3

   Measure resistance

   Measure the internal resistance of the sensor. If the sensor is open, shorted, or reading out of the acceptable temperature-resistance curve, it has failed and must be replaced.

4. 4

   Check wiring continuity

   If the sensor tests good, use a multimeter to check the continuity of the wiring harness back to the Engine Controller and Instrumentation Controller. Repair any broken wires or shorts to ground.

5. 5

   Replace sensor

   If replacing the sensor, unthread the old sensor from the intake piping, install the new sensor, and torque to OEM specifications.

6. 6

   Reconnect wiring

   Reconnect the wiring harness.

7. 7

   Clear codes and verify

   Turn the key on and use a diagnostic tool or the tractor's instrumentation display to clear the stored fault codes. Run the engine to verify the code does not return.