Case IH 488 – Engine Control Module (ECM) / Engine ECU: Intake Manifold Temperature level has exceeded the warning limit

The Engine Control Module (ECM) has detected that the intake air temperature is valid but operating above the normal operational range (moderately severe level).

• MX Magnum
• STX Steiger
• Case IH MX Magnum Series (MX255, MX285)
• Case IH TG Series Tractors (TG210, TG230, TG255, TG285)
• Case IH STX Steiger Series (STX440)
• Case IH FLX4510
• Case IH Combines (Cummins ISC, ISL, QSC, QSX)

1. 1

   Check for Airflow Restrictions: Inspect the air filter for heavy dirt accumulation and check the intake piping for any blockages.

2. 2

   Inspect the Charge Air Cooler (Intercooler): Ensure the exterior fins of the charge air cooler are not plugged with chaff, dirt, or debris, which would prevent the intake air from cooling down.

3. 3

   Verify Sensor Accuracy: Use a diagnostic service tool or a digital multimeter alongside an infrared thermometer to verify if the sensor's temperature reading matches the actual physical temperature of the intake manifold.

4. 4

   Wiring and Circuit Check: Inspect the wiring harness and the 2-pin connector leading to the sensor for chafing, corrosion, or short circuits.

1. 1

   Preparation

   Turn off the engine, remove the key, and allow the engine to cool completely.

2. 2

   Locate the Sensor

   Locate the intake manifold temperature sensor. On most Case IH/Cummins 8.3L and 9.0L engines, it is threaded directly into the intake manifold, often near cylinder number 6.

3. 3

   Clear Obstructions

   If necessary, remove the left/right fan shields or loosen the harness and hose retainers on the side of the engine to gain clear access to the sensor.

4. 4

   Disconnect Wiring

   Carefully depress the locking tab and disconnect the 2-pin oval Deutsch electrical plug from the sensor.

5. 5

   Remove the Sensor

   Use a deep socket or wrench to unthread the faulty sensor from the manifold.

6. 6

   Install the New Sensor

   Ensure the O-ring is properly seated on the new sensor. Thread the new sensor into the manifold (M14 x 1.5 thread) and tighten to OEM torque specifications.

7. 7

   Reconnect

   Reconnect the electrical harness plug until it clicks into place. Re-secure any hose retainers or shields that were removed.

8. 8

   Clear Codes

   Use an electronic service tool to clear the inactive fault code 488 from the ECM. Run the machine under load to verify the code does not return.