P1113
SubaruIntake Air Temperature (IAT) Sensor Open or Short Circuit. This code indicates that the Engine Control Module (ECM) has detected an electrical malfunction within the IAT sensor circuit, meaning the sensor is either not receiving a signal (open) or there's an electrical short.
Medium SeverityThis code means your vehicle's Intake Air Temperature (IAT) sensor, which measures the temperature of the air entering the engine, has an electrical problem like a broken wire or a short circuit. This can lead to the engine receiving incorrect air temperature readings, impacting fuel mixture and potentially causing reduced fuel efficiency and increased emissions.
⚠️ Before You Begin (Safety First)
Always ensure the vehicle is turned off and the key is removed before performing any inspection or repair. Disconnect the battery's negative terminal to prevent accidental electrical shorts or injury when working with electrical components. Allow the engine to cool down completely if you need to access parts near hot engine components.
Common Symptoms
- Check Engine Light illuminated
- Reduced fuel economy
- Rough idle or stalling
- Hesitation during acceleration
- Difficulty starting in extreme temperatures (cold or hot)
Common Causes
- Faulty Intake Air Temperature (IAT) sensor
- Open circuit or short circuit in the IAT sensor wiring harness
- Corroded or damaged IAT sensor connector
- Damaged ECM (rare)
Frequently reported on: Subaru Impreza 2005-2010, Subaru Forester 2006-2011, Subaru Legacy 2007-2012, Subaru Outback 2007-2012, Subaru WRX 2008-2014
Diagnostic Steps
- Locate the 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.
- Carefully disconnect the electrical connector from the IAT sensor.
- Using a multimeter, test the resistance of the IAT sensor at various ambient temperatures, comparing it to manufacturer specifications. An open circuit (infinite resistance) or a very low resistance (short) indicates a faulty sensor.
- Check for continuity and voltage at the IAT sensor harness connector. Ensure there is proper reference voltage and a good ground.
- If the sensor tests bad or wiring issues are confirmed, replace the IAT sensor or repair the damaged wiring/connector.
- Clear the fault code using an OBD-II scanner and test drive the vehicle.
👨🔧 When to Call a Professional
If you've checked the sensor and wiring and the issue persists, or if you're not comfortable performing electrical diagnostics, it's best to consult a qualified Subaru technician to avoid further damage to the wiring harness or ECM.
Commonly Asked Questions
What does the IAT sensor do?
The IAT sensor measures the temperature of the air entering the engine. This information is crucial for the Engine Control Module (ECM) to calculate the correct fuel mixture for optimal performance and emissions.
Can I drive with a P1113 code?
While you can typically drive with a P1113 code, it's not recommended for extended periods. The engine's performance, fuel economy, and emissions will likely be negatively affected, and ignoring it could potentially lead to other issues over time.
Is an IAT sensor hard to replace?
For most vehicles, replacing the IAT sensor is a straightforward process, often involving disconnecting a connector and unscrewing or unlatching the sensor. It's usually considered an easy DIY repair.
How can I test the IAT sensor?
You can test an IAT sensor using a multimeter to measure its resistance. The resistance should change predictably with temperature; an open circuit or very low resistance often indicates a faulty sensor. You'll need to consult your vehicle's service manual for specific resistance values at different temperatures.
Will replacing the IAT sensor fix my P1113 code?
In many cases, yes. A faulty IAT sensor is a common cause of this code. However, if the issue is with the wiring harness or the connector, replacing only the sensor will not resolve the problem, and those components will need to be repaired or replaced.