Intake Air Temperature Sensor Circuit High Input (Bank 1)
The P0113 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the Intake Air Temperature (IAT) sensor that is higher than the expected range, typically above 4.9 volts. This usually means the sensor is reading extremely cold air (e.g., -40°F) or there is an open circuit. The IAT sensor is a thermistor that changes resistance with temperature; high voltage suggests high resistance, often due to a faulty sensor, damaged wiring, or poor electrical connections. This code affects fuel mixture and ignition timing, potentially causing drivability issues.
01. Most Common Causes
- Faulty Intake Air Temperature (IAT) sensor
- Open or shorted wiring in the IAT sensor circuit
- Poor electrical connection at the IAT sensor connector
- Corrosion or damage to the sensor terminals
- ECM issues (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation during acceleration
- Hard starting in cold weather
- Black smoke from exhaust (rich mixture)
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm P0113 and check for other codes.
Step 2: Visually inspect the IAT sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Disconnect the IAT sensor and measure resistance; compare to manufacturer specs (e.g., 2-3 kΩ at 68°F).
Step 4: Check voltage at the sensor connector with the ignition on; should be around 5V reference and signal wire near 0V when sensor is warm.
Step 5: If sensor and wiring are good, test the ECM by backprobing the signal wire and monitoring voltage changes with temperature.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe for short trips, but prolonged driving can cause poor fuel economy, rough running, and potential damage to the catalytic converter due to incorrect air-fuel mixture. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150, including parts and labor. The IAT sensor itself is inexpensive (around $20-$50), and labor is usually under an hour. Wiring repairs may add to the cost.