P1113
FordFord-specific code indicating an open or short circuit in the Intake Air Temperature (IAT) sensor circuit, specifically out of self-test range.
Medium SeverityThis code means the Intake Air Temperature Sensor circuit is experiencing an electrical fault, either a break in the wiring (open circuit) or a short circuit. This prevents the engine control module from accurately reading the temperature of the air entering the engine, which can lead to incorrect fuel mixture calculations and reduced engine performance.
⚠️ Before You Begin (Safety First)
Always wear appropriate personal protective equipment, such as gloves and eye protection. Before working on any electrical components, always disconnect the negative battery terminal to prevent accidental shocks or damage to the vehicle's electrical system. Allow the engine to cool down before handling any components under the hood.
Common Symptoms
- Check Engine Light illumination
- Poor fuel economy
- Rough idle or stalling
- Reduced engine power
- Difficulty starting the engine (especially in extreme temperatures)
Common Causes
- Faulty Intake Air Temperature (IAT) sensor
- Damaged or corroded wiring in the IAT sensor circuit
- Loose or corroded electrical connectors at the IAT sensor or ECM
- Short circuit in the IAT sensor wiring to ground or power
- Open circuit in the IAT sensor wiring
Frequently reported on: Ford F-150 (1997-2003), Ford Explorer (1996-2001), Ford Ranger (1998-2004), Ford Focus (2000-2007), Ford Crown Victoria (1998-2005)
Diagnostic Steps
- Locate the Intake Air Temperature (IAT) sensor, typically found in the intake manifold or air intake tube after the air filter.
- Visually inspect the IAT sensor and its electrical connector for any obvious signs of damage, corrosion, or loose connections.
- Disconnect the IAT sensor connector and use a multimeter to check for continuity in the wiring harness between the sensor connector and the engine control module (ECM) connector, referring to a vehicle-specific wiring diagram.
- Measure the resistance of the IAT sensor itself using a multimeter; compare the reading to factory specifications (resistance should change with temperature).
- If the sensor tests faulty, replace it with a new OEM or equivalent quality part.
- If wiring or connectors are damaged, repair or replace them as necessary.
- Clear the P1113 code from the ECM using an OBD-II scanner and test drive the vehicle to confirm the repair.
👨🔧 When to Call a Professional
If you've replaced the IAT sensor and thoroughly checked the wiring, but the code P1113 persists, it may indicate a deeper electrical issue within the vehicle's wiring harness or a fault with the engine control module (ECM) itself. In such cases, professional diagnostic equipment and expertise are needed to trace and repair the complex electrical pathways.
Commonly Asked Questions
Can I drive with a P1113 code?
While you might be able to drive, it's not recommended for extended periods. The engine's performance and fuel economy will be negatively impacted, and prolonged driving with an inaccurate air temperature reading could potentially lead to other engine issues.
What is an IAT sensor and what does it do?
The Intake Air Temperature (IAT) sensor measures the temperature of the air entering your engine. This information is crucial for the engine's computer to calculate the correct fuel-to-air mixture for optimal combustion.
How do I test my IAT sensor?
You can test an IAT sensor using a multimeter to measure its resistance. The resistance should change significantly with temperature. Consult your vehicle's service manual for specific resistance values at different temperatures.
Is an IAT sensor expensive to replace?
The IAT sensor itself is typically an inexpensive part, often costing between $20-$50. Labor costs for replacement are usually minimal since it's an easy component to access and replace.
What if the wiring is the problem, not the sensor?
If testing confirms the sensor is good, then the problem lies in the wiring or connector. You'll need to carefully inspect the wires leading to the IAT sensor for any breaks, frays, corrosion, or shorts. Repairing wiring can be more involved than just replacing the sensor.