Sensor signal wire chafed and shorted to ground or to a nearby metal bracket; Failed Intake Air Temperature Sensor 2 with an internal short; Corroded, pushed-back or water-intruded connector pins at the sensor or computer; Open or high-resistance ground circuit shared with other sensors, skewing the reading; Aftermarket intake or wiring repair that routed the sensor harness against a hot or moving component; Faulty engine computer driver on the signal input, though this is the least common cause

DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P0097

P0097Intake Air Temperature Sensor 2 Circuit Low

Q: What does code P0097 mean?

Intake Air Temperature Sensor 2 Circuit Low. P0097 means the engine computer has detected an abnormally low voltage on the signal circuit of Intake Air Temperature Sensor 2, which is a second temperature sensor used on some engines to monitor air entering the intake system. The computer expects a voltage within a calibrated range for the current air temperature, and a low reading tells it the sensor circuit is shorted to ground or otherwise reporting a temperature far hotter than reality.

P0097 means the engine computer has detected an abnormally low voltage on the signal circuit of Intake Air Temperature Sensor 2, which is a second temperature sensor used on some engines to monitor air entering the intake system. The computer expects a voltage within a calibrated range for the current air temperature, and a low reading tells it the sensor circuit is shorted to ground or otherwise reporting a temperature far hotter than reality.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or poor driveability when the engine is cold if the false hot reading leans out the mixture
Reduced fuel economy or black smoke from over-fuelling in some control strategies
Elevated idle speed or unstable idle during warm-up
Failed emissions test or a pending code that returns after clearing
In rare cases, a no-start or hard-start condition when the false reading is extreme

Common causes, most likely first

Sensor signal wire chafed and shorted to ground or to a nearby metal bracket
Failed Intake Air Temperature Sensor 2 with an internal short
Corroded, pushed-back or water-intruded connector pins at the sensor or computer
Open or high-resistance ground circuit shared with other sensors, skewing the reading
Aftermarket intake or wiring repair that routed the sensor harness against a hot or moving component
Faulty engine computer driver on the signal input, though this is the least common cause

How to diagnose and fix it

Clear the code and road-test to confirm it returns, then record freeze-frame data to see the reported temperature versus ambient
Inspect the sensor connector and the full harness run for chafing, pin damage, corrosion or moisture intrusion
Disconnect the sensor and measure signal-circuit voltage with the key on to see whether the computer pulls the line high or the short remains
Measure sensor resistance across its terminals and compare with the temperature-resistance chart for the engine family
Check the sensor ground circuit for excessive resistance with a voltage drop test under load
Repair or replace the damaged section of harness, then re-test before condemning the sensor
Replace Intake Air Temperature Sensor 2 only after the wiring and ground tests pass, then clear and verify the code stays away

Why a low reading is not always the sensor

A short to ground anywhere along the signal wire produces the same low-voltage reading as a failed sensor, so technicians who replace the sensor first often see the code return within a few drive cycles.
Intake Air Temperature Sensor 2 is often mounted in the intake manifold or charge pipe rather than the air box, so heat soak and vibration damage to its harness are common causes that a visual check of the air box will never reveal.
On engines that use the second sensor to cross-check the first, a false hot reading can make the computer distrust both sensors and substitute a default value, which may set companion codes and mask the real fault.
Water intrusion into the connector after engine washing or heavy rain can create a temporary short that sets the code only under damp conditions, so a dry-weather inspection can miss the problem entirely.
A shared ground circuit with high resistance can pull the signal voltage low without any fault in the sensor or its positive wiring, which is why a ground voltage drop test belongs in every diagnosis of this code.

Can I keep driving with P0097?

The vehicle is generally safe to drive with P0097 because the computer substitutes a default air temperature and keeps managing the engine, but avoid heavy towing or sustained high-load driving until it is repaired. If the engine runs rough, idles poorly or stalls, have it diagnosed promptly rather than continuing to drive.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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