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 4.6 volts). This usually means the sensor is reading extremely cold air or there is an open circuit. The IAT sensor is a thermistor that changes resistance with temperature; high voltage corresponds to low temperature (high resistance). Common causes include a faulty IAT sensor, wiring issues (open or short to voltage), or a poor connection. This code can affect fuel mixture and engine performance.
1. Most Common Causes
- Faulty IAT sensor (internal open circuit)
- Open circuit in sensor wiring (signal or ground wire broken)
- Signal wire shorted to battery voltage or 5V reference
- Sensor connector disconnected, loose, or with corroded/damaged terminals
- Internal PCM failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor fuel economy
- Rough idle or hesitation
- Hard starting in cold weather
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the IAT sensor connector and wiring for damage or corrosion.
Step 3: Measure voltage at the IAT sensor signal wire with the engine off; should be around 2-3 volts at room temperature. If near 5 volts, suspect open circuit.
Step 4: Test the IAT sensor resistance; compare to manufacturer specifications (e.g., ~2.5k ohms at 68°F).
Step 5: If sensor and wiring are good, check for ECM issues or perform a wiggle test to find intermittent faults.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but the engine may run rich or lean, potentially causing damage to the catalytic converter or oxygen sensors. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Typically $50-$150 for parts and labor. The IAT sensor itself costs $20-$50, and labor is about $30-$100 depending on vehicle accessibility.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.