P00A8
Intake Air Temperature Sensor 2 Circuit High Bank 2.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 0
- AreaFuel and air metering, auxiliary emission controls
- A8
- FaultThe specific fault in that area
What it means
P00A8 means the engine control unit has seen the signal from intake air temperature sensor 2 on bank 2 sit abnormally high in voltage, which it reads as an implausibly cold air temperature. This usually points to an open circuit, a poor connection or a sensor that has failed open. The exact position of sensor 2 (for example in the intake manifold or the charge air path) depends on the model and engine.
Symptoms
- Engine warning light on
- Hard or extended cranking when starting, especially from cold
- Rough idle or hesitation under load
- Reduced power or the engine running in a limited-performance mode
- Poor fuel economy
- Other intake air temperature or bank 2 related codes stored alongside
Possible causes
- Intake air temperature sensor 2 (bank 2) faulty or failed open-circuitlikely
- Unplugged, corroded, loose or damaged sensor connector terminalslikely
- Open circuit in the signal or ground wire between the sensor and the control unitlikely
- Signal wire shorted to a voltage supply or to the sensor reference feedpossible
- Chafed, heat-damaged or rodent-damaged harness near the intake or turbocharger pipeworkpossible
- Water ingress into the connector or sensor bodypossible
- Fault inside the engine control unit or an outdated calibration, where the manufacturer has identified one for that modelrare
How to diagnose
- Read all stored and pending codes and the freeze frame data, noting engine temperature, load and whether other intake temperature codes are present.
- Check live data: compare intake air temperature sensor 2 with sensor 1 and the coolant temperature on a cold engine; a reading stuck at the lowest value suggests an open circuit.
- Inspect the sensor, connector and nearby harness for damage, corrosion, water, oil contamination, poor seating and signs of chafing or heat damage.
- Disconnect the connector and check for corrosion or spread terminals, then check the terminal tension.
- Using the manufacturer wiring diagram, back-probe the sensor connector and check the reference voltage and the ground; the model's wiring layout determines the pins.
- Measure the sensor resistance at a known temperature and compare it with the manufacturer's specification.
- Check the signal and ground wires for continuity to the control unit and for shorts to voltage or ground.
- If wiring and sensor are good, check for relevant technical service bulletins or calibration updates for that model before suspecting the control unit.
How to fix
- Replace intake air temperature sensor 2 if its resistance is out of specification or it has failed open.
- Clean, repair or replace the damaged connector terminals and ensure the connector locks fully.
- Repair or replace the open or damaged section of the signal or ground wire.
- Repair any short to voltage in the harness and secure the loom away from heat and sharp edges.
- Dry and seal any water ingress and fix the cause of the leak.
- Where a manufacturer-identified fault exists, update the control unit calibration or repair the control unit.
Can I keep driving?
The car can usually be driven short distances, as the control unit substitutes a default air temperature value, but performance, economy and starting may suffer and the fault could get worse. Get it checked soon, and avoid heavy loads or long journeys if the car goes into reduced power mode.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.