A short to ground in the intake air temperature sensor 3 signal wire, often from chafed insulation or a pinched harness.; A failed intake air temperature sensor 3 that has internally shorted and reads a fixed low resistance.; Corroded, loose, or water-intruded terminals at the sensor connector or the powertrain control module connector.; A short to ground in the sensor's reference voltage circuit, pulling the signal low.; A faulty powertrain control module, though this is rare and should be diagnosed last.; Aftermarket wiring repairs or accessories that have tapped into the sensor circuit incorrectly.

DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P00EF

P00EFIntake Air Temperature Sensor 3 Circuit Low Bank 2

Q: What does code P00EF mean?

Intake Air Temperature Sensor 3 Circuit Low Bank 2. P00EF indicates that the powertrain control module has detected an abnormally low voltage signal on the intake air temperature sensor 3 circuit for bank 2, which typically means the sensor is reporting a hotter intake charge than is physically possible. The computer compares the sensor's return voltage against expected values and flags the circuit when the signal falls below the calibrated threshold for a set time.

P00EF indicates that the powertrain control module has detected an abnormally low voltage signal on the intake air temperature sensor 3 circuit for bank 2, which typically means the sensor is reporting a hotter intake charge than is physically possible. The computer compares the sensor's return voltage against expected values and flags the circuit when the signal falls below the calibrated threshold for a set time.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Rough idle or hesitation when the engine is cold, because the computer may enrich the fuel mixture incorrectly.
Poor fuel economy as the module substitutes a default intake air temperature value.
A slight loss of power or sluggish throttle response under light load.
In rare cases, a no-start condition if the sensor signal is shorted directly to ground.
Intermittent drivability issues that appear only in damp or hot weather.

Common causes, most likely first

A short to ground in the intake air temperature sensor 3 signal wire, often from chafed insulation or a pinched harness.
A failed intake air temperature sensor 3 that has internally shorted and reads a fixed low resistance.
Corroded, loose, or water-intruded terminals at the sensor connector or the powertrain control module connector.
A short to ground in the sensor's reference voltage circuit, pulling the signal low.
A faulty powertrain control module, though this is rare and should be diagnosed last.
Aftermarket wiring repairs or accessories that have tapped into the sensor circuit incorrectly.

How to diagnose and fix it

Connect a scan tool and record the freeze-frame data and intake air temperature sensor 3 voltage with the key on and engine off.
Visually inspect the sensor, its connector, and the harness for chafing, corrosion, or signs of rodent damage.
Disconnect the sensor and measure resistance across its terminals, comparing the reading to the temperature-resistance chart for the vehicle.
With the sensor disconnected, measure voltage on the signal wire from the powertrain control module to confirm whether the short is in the harness or the sensor.
Wiggle-test the harness while watching live data to catch intermittent shorts that only appear under vibration.
Repair or replace the faulty section of harness, terminals, or the sensor itself, then clear the code and verify the intake air temperature reading matches ambient.
Perform a road test with the scan tool recording to confirm the code does not return under load and temperature changes.

What the low-voltage reading really means

A low signal on this circuit almost always means a short to ground, not an open circuit, so replacing the sensor without checking the harness often wastes money.
The intake air temperature sensor 3 is frequently integrated into a mass airflow sensor or a combined pressure-temperature sensor on many engines, so the repair may involve the whole assembly rather than a stand-alone part.
Bank 2 designation can confuse technicians on inline engines, where the bank 2 label may refer to a specific intake runner or a sensor mounted after a split in the intake tract.
Water intrusion into the connector after engine washing or heavy rain is a common cause that leaves no visible damage to the sensor itself.
A shorted sensor can pull down the shared reference voltage for other sensors on the same circuit, causing multiple unrelated codes that disappear once the short is fixed.

Can I keep driving with P00EF?

The vehicle is generally safe to drive because the computer substitutes a default intake air temperature value, but avoid heavy towing or sustained high-load driving until the fault is repaired. If the engine runs rough or stalls, stop driving and have the circuit diagnosed promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.