Engine Intake Air Temperature Sensor Circuit Low
Indicates the intake air temperature is below the normal operating range.
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What it means (plain English)
The engine control computer is getting a reading from the intake air temperature sensor that's lower than expected, pointing to a potential fault with the sensor or its wiring.
What the computer is actually seeing
The ECM is expecting an intake air temperature (IAT) reading to be around 50°F to 140°F (10°C to 60°C) during normal operation. When it sees a value below this range, that triggers the fault code.
What a healthy reading looks like
IAT readings should be between 10°C to 60°C (50°F to 140°F) during engine operation at normal temperature; below this range indicates a problem.
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 the intake air temperature sensor wiring for any visible damage or corrosion. If damaged, repair or replace.
- 22. Inspect the electrical connectors on the intake air temperature sensor for looseness or corrosion. Clean and repair as needed.
- 33. Measure the voltage at the IAT sensor connector with the ignition on and the engine off. Expected voltage should be around 0.5V to 4.5V depending on the temperature (sensor specs). If voltage is outside this range, replace the sensor.
- 44. If the sensor voltage is normal, use a scan tool to check for other related fault codes to determine if there may be an issue with the ECM. If none, consider the sensor faulty.
Common causes
- Faulty intake air temperature sensor
- Damaged wiring or connectors in sensor circuit
- Loose or corroded electrical connections
- Faulty ECM (less likely)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means you can drive, but fix it soon to avoid performance issues.
Will the code come back after I fix it?
If the sensor or wiring is faulty, yes. Make sure to do a thorough check before clearing it.
Why does this code pair with SPN 2954?
SPN 2954 is the high temperature fault; it's common to see both because issues with the sensor can cause both readings.
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