Here's how to troubleshoot and potentially repair the P0119 code:
1. Inspection and Visual Check:
* Locate the IAT sensor: This is usually located in the intake tube, close to the mass airflow sensor (MAF sensor). Consult your F-150's repair manual for the exact location.
* Inspect the sensor: Look for any obvious physical damage, such as cracks, loose wires, or corrosion. Pay close attention to the connector.
* Check wiring: Examine the wiring harness leading to the sensor for any damage, breaks, or loose connections. Look for chafing against the engine or other components.
2. Testing:
* Disconnect the IAT sensor connector: With the engine OFF, carefully disconnect the connector from the IAT sensor.
* Check for corrosion: Clean the connector pins with contact cleaner and a small brush. Ensure good contact.
* Check the connector for damage: Look for broken or bent pins.
* Use a multimeter: You'll need a multimeter to test the sensor's resistance and voltage. Refer to your repair manual for the correct specifications for your specific IAT sensor. The resistance should change with temperature. A faulty sensor will likely show incorrect resistance readings.
* Check the wiring: With the multimeter, test the resistance and continuity of the wiring harness to and from the PCM. A break or short circuit will show infinite resistance or a low resistance where it shouldn't be.
3. Repair or Replacement:
Based on your inspection and tests:
* Clean the connector: If corrosion or a loose connection was the issue, clean the connector and reconnect it. Clear the code and test drive the vehicle.
* Repair wiring: If there's damage to the wiring harness, repair it using appropriate connectors and wiring.
* Replace the IAT sensor: If the sensor is faulty, replace it with a new one from a reputable parts supplier. Ensure you get the correct part number for your specific vehicle.
* Replace the PCM (rare): In very rare cases, a faulty PCM could be the culprit, but this is less likely than a bad sensor or wiring. This is a much more expensive and involved repair.
Important Considerations:
* Repair manual: A repair manual specific to your 2004 Ford F-150 is invaluable for accurate location of components, testing procedures, and specifications.
* Safety: Disconnect the negative battery terminal before working on any electrical components.
* Professional help: If you're not comfortable working with automotive electrical systems, take your vehicle to a qualified mechanic.
After any repairs, clear the trouble code using an OBD-II scanner and test drive the vehicle to ensure the problem is resolved. If the code returns, further diagnosis may be required. Remember to always consult your vehicle's repair manual for specific procedures and specifications.
