Case IH 155 – Engine Control Module (ECM): Intake Manifold Temperature level has exceeded the warning limit

The Intake Manifold Air Temperature (IMAT) sensor detects that the intake air temperature is dangerously high (e.g., exceeding 93.3°C/200°F or 132°C/270°F). When this code is active, the engine will experience a progressive power and speed de-rate, and if the Engine Protection Shutdown feature is enabled, the engine will shut down 30 seconds after the red STOP lamp starts flashing to prevent catastrophic damage.

• MX Magnum
• STX Steiger
• Case IH MX Magnum Series
• MX255
• MX285
• Case IH TG Series
• TG210
• TG230
• TG255
• TG285
• Case IH STX Steiger Series
• STX280
• STX440
• STX500
• STX550

1. 1

   Inspect the air intake system for airflow restrictions, such as a clogged, dirty, or inadequate capacity air cleaner element

2. 2

   Check the cooling system for low coolant levels, a blocked radiator, or recirculation of hot discharge air into the engine intake

3. 3

   Verify the engine compartment temperature is not excessively high and ensure the sensor is not located near an extreme, unshielded heat source

4. 4

   Test the sensor and wiring: check the 5-volt supply circuit, inspect the harness for damaged, bent, loose, or corroded pins, and use a manual thermometer to verify if the actual air temperature matches the sensor's reading

1. 1

   Power Down

   Turn the keyswitch to the OFF position.

2. 2

   Clear Restrictions

   If the diagnostic checks revealed a clogged air filter or blocked radiator, clean or replace the air filter and clear any debris from the cooling package.

3. 3

   Locate the Sensor

   The intake manifold temperature sensor is typically located on the side or top half of the intake manifold, near the middle or front of the cylinder head.

4. 4

   Remove the Sensor

   Disconnect the electrical plug for the intake manifold temperature sensor. Unthread the sensor from the intake manifold.

5. 5

   Install the New Sensor

   Thread the replacement sensor into the manifold and tighten to OEM torque specifications. Reconnect the electrical harness plug.

6. 6

   Validate the Repair

   Turn the keyswitch ON, start the engine, and let it idle for at least 1 minute. The fault code status displayed on your electronic service tool should change to INACTIVE, and the ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.