P1110
HondaIntake Air Temperature (IAT) Sensor Circuit Open or Short (Dual/Compound).
Medium SeverityThis code indicates an electrical issue, either an open circuit or a short circuit, within the Intake Air Temperature (IAT) sensor wiring or the sensor itself. Consequently, the vehicle's engine control unit (ECU) receives inaccurate or no data regarding the temperature of the air entering the engine, leading to suboptimal fuel mixture adjustments and potentially affecting engine performance and fuel efficiency.
⚠️ Before You Begin (Safety First)
Always wear appropriate personal protective equipment (PPE) such as safety glasses and gloves when working on your vehicle. Disconnect the battery's negative terminal before performing any electrical work to prevent accidental short circuits or electrical shocks. Allow the engine to cool down before handling any engine components.
Common Symptoms
- Check Engine Light illuminated
- Decreased fuel economy
- Rough idling
- Reduced engine power
- Hard starting in extreme temperatures
- Black smoke from exhaust (in rich conditions)
Common Causes
- Faulty Intake Air Temperature (IAT) sensor
- Corroded or damaged IAT sensor connector
- Open or short circuit in the IAT sensor wiring harness
- Poor electrical connection at the IAT sensor or ECU
- Damaged Engine Control Unit (ECU) (less common)
Frequently reported on: Honda Civic (2001-2005), Honda Accord (1998-2002), Honda CR-V (1997-2001), Honda Odyssey (1999-2004)
Diagnostic Steps
- Visually inspect the IAT sensor and its wiring for any signs of damage, corrosion, or loose connections.
- Disconnect the IAT sensor and use a multimeter to check for continuity in the sensor's circuit as per your vehicle's service manual specifications.
- Check the voltage supply to the IAT sensor connector to ensure it is receiving proper power from the ECU.
- If the sensor is faulty or the wiring shows damage, replace the IAT sensor or repair the wiring harness as needed.
- Clear the P1110 code from the ECU using an OBD-II scanner and perform a test drive to confirm the repair.
👨🔧 When to Call a Professional
If after inspecting the wiring and replacing the IAT sensor, the P1110 code persists, or if you are uncomfortable performing electrical diagnostics, it is best to consult a professional automotive technician. This could indicate a more complex issue within the engine's wiring harness or the ECU itself.
Commonly Asked Questions
Can I drive with a P1110 code?
While you can typically drive with a P1110 code, it's not recommended for long periods as it can lead to decreased fuel economy and potential engine performance issues.
Where is the IAT sensor located?
The IAT sensor is usually located in the air intake ducting, either in the air cleaner housing or directly in the intake manifold, after the air filter and before the throttle body.
How do I test the IAT sensor?
You can test the IAT sensor by checking its resistance with a multimeter across its terminals. The resistance should change with temperature according to the manufacturer's specifications.
Is an IAT sensor replacement difficult?
Generally, replacing an IAT sensor is a straightforward process, often involving disconnecting a connector and unscrewing the sensor, making it an easy DIY task.
Can a dirty air filter cause P1110?
A dirty air filter itself is unlikely to directly cause a P1110 code, which points to an electrical circuit issue. However, proper air flow is important for sensor accuracy, so ensuring the air filter is clean is always good practice.