Intake Air Temperature Sensor 1
The engine control unit (ECU) detected a fault with the intake air temperature sensor 1 reading.
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What it means (plain English)
The intake air temperature sensor measures the temperature of the air entering the engine. If it’s faulty, the computer may not be able to adjust fuel delivery properly, affecting performance.
What the computer is actually seeing
The ECU expects a voltage from the intake air temperature sensor proportional to air temperature, usually around 0.5V to 4.5V corresponding to -40°C to +125°C. A reading outside this range indicates a problem.
What a healthy reading looks like
Expected voltage range is 0.5V to 4.5V, corresponding to intake air temperatures of -40°C to +125°C.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check wiring and connector. Look for frays, corrosion, and loose connections. Eliminate any visual issues.
- 22. Using a multimeter, test the sensor voltage with the ignition on (engine off). Should be between 0.5V and 4.5V. If not, suspect sensor failure.
- 33. If the voltage is within range, start the engine and monitor the sensor output at idle. Again, should be between 0.5V and 4.5V. If it goes to 0V or spikes, replace the sensor.
- 44. If the sensor reads correctly, use a scan tool to check for software updates or additional fault codes related to the ECU.
Common causes
- Faulty intake air temperature sensor
- Wiring damage between sensor and ECU
- Poor connector contact or corrosion
- ECU software issue
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
With a moderate severity, it’s best to get it fixed soon but driving might be okay, just expect poor performance or fuel economy.
Will this code come back after clearing?
If the underlying issue isn't resolved, yes, the code will likely come back after clearing.
Why does this code pair with SPN 2518?
SPN 2518 is often related as it measures air flow, which, along with temperature, affects engine performance.
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