Engine Intake Air Temperature Sensor A Circuit Range/Performance Problem
The intake air temperature sensor signal is out of range or performance is poor.
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What it means (plain English)
The sensor that measures the temperature of the air entering the engine is either reading too high or too low, affecting engine performance.
What the computer is actually seeing
The engine control unit expects the intake air temperature to be in a certain range (typically between -40°F and 212°F). If the reading goes below 0°F or above 220°F, it sets this fault code.
What a healthy reading looks like
Normal intake air temperature should be between -40°F to 212°F (-40°C to 100°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. Inspect wiring and connector at the intake air temperature sensor for damage, corrosion, or loose connections. Decision: If damaged, repair or replace; if not, move to next step.
- 22. Measure the voltage at the intake air temperature sensor connector. It should typically range from 0.5V (cold) to 4.5V (hot). Decision: If voltage is outside this range, replace the sensor; if within range, move to next step.
- 33. Check the air intake system for leaks or restrictions that could affect temperature readings. Decision: If found, repair the leak; if not, move to next step.
- 44. Use a scan tool to check if any other related fault codes are present (like SPN 3141 or SPN 3142). Decision: If yes, diagnose those codes accordingly; if no, verify the engine control module (ECM) software is up-to-date.
Common causes
- Faulty intake air temperature sensor
- Wiring issues or bad connections
- Air intake system leaks
- Engine control module (ECM) software issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but expect reduced performance and potential increased emissions; get it checked soon.
Will this code come back after clearing?
Yes, if the underlying issue isn’t fixed, the code will return after a few drive cycles.
Why does this code sometimes pair with other codes?
Related codes often indicate issues with the same sensor or related systems, impacting performance or readings.
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