P0097 - Intake Air Temperature Sensor 2 Circuit Low Input
Last updated:
System
Powertrain (Engine & Gearbox)
Related Fault Codes
Technical Description
P0097 is triggered when the Engine Control Unit (ECU) detects a voltage signal from the Intake Air Temperature (IAT) sensor 2 that is below the expected range (typically less than 0.1V to 0.2V). IAT sensor 2 is usually located after the charge air cooler (intercooler) on forced induction engines to monitor the air temperature entering the combustion chamber. As the sensor is an NTC thermistor, a 'low input' signal generally indicates a short circuit to ground in the signal wire or a sensor internal failure representing an impossibly high temperature.
Possible Causes
Short to ground in the IAT 2 signal circuit
Faulty IAT 2 sensor (internal short)
Corroded or damaged connector causing a bridge to ground
Internal ECU failure (shorted input pin)
Symptoms
Recommended Solution
- Visual Inspection: Check wiring and connectors for the IAT 2 sensor (look for chafing or melted insulation touching the engine block).
- Voltage Test: Disconnect the sensor. Turn ignition ON. Measure between reference wire and ground. You should see approx. 5.0V. If correct, focus on the signal return wire.
- Resistance Test: Measure the sensor's resistance. At approx. 20°C (68°F), it should typically be between 2000-3000 Ohms. 0 Ohms indicates an internal short.
- Live Data: Check IAT 2 readings via OBD scanner. If it shows an impossibly high temperature (e.g., +150°C), there is a short to ground.
- Replacement: Replace the IAT 2 sensor if resistance values are out of spec or if the code changes to P0098 (circuit high) when disconnected.
Mechanic's Tip
Before replacing expensive components, always double-check wiring and connections. 80% of all sensor faults are actually due to corroded contacts or broken wires.
Do you also have
other fault codes?
See how P0097 connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.