Fuel and air

P00A5 — Intake Air Temperature Sensor 2 Circuit Malfunction, Bank 2

Severity: medium Safe to drive

What P00A5 means

P00A5 means the engine control unit (ECU) has detected a signal outside the expected range in the bank 2 intake air temperature sensor 2 (IAT 2) circuit. The sensor is a thermistor whose resistance changes with temperature, which changes the voltage the ECU reads. The ECU uses this to estimate air density for fuel and ignition timing calculations. A voltage that is too high or too low is treated as a circuit fault.

Symptoms

  • Check Engine light on
  • Poor fuel economy
  • Rough idle
  • Hesitation when accelerating
  • Reduced engine power
  • Harder starting when cold

Possible causes

  1. Failed intake air temperature sensor 2
  2. Open circuit in the sensor wiring
  3. Short to ground or to voltage in the harness
  4. Corroded terminals or a loose connector
  5. Chafed or heat-damaged wiring near hot or moving parts
  6. Faulty ECU (rare)

How to diagnose

  1. Scan for codes and freeze frame data, clear the code and see whether it returns
  2. Compare IAT 2 and IAT 1 readings on a cold engine; both should be close to ambient temperature
  3. Inspect the sensor connector and harness for chafing, melted insulation and corrosion
  4. Unplug the sensor and check for the reference voltage (typically about 5 V) and a good ground
  5. Measure the sensor resistance and compare it to the specification at a known temperature
  6. Test the wiring between the sensor and ECU for opens and shorts to ground or power
  7. If the sensor and wiring are good, check the ECU

Common fixes

  • Replace intake air temperature sensor 2
  • Repair damaged wiring or replace the connector
  • Clean the terminals and secure the connector
  • Replace or reprogram the ECU if confirmed faulty

Questions and answers

Can I drive with code P00A5?

Usually yes, for short trips. The ECU uses a fallback temperature value, but fuel economy and performance may suffer, so get it diagnosed soon.

What does bank 2 mean in P00A5?

Bank 2 is the side of the engine that does not contain cylinder 1, found on V-type and flat engines. It points to the second IAT sensor circuit.

Do I always need a new sensor?

No. A corroded connector or damaged wire is often the cause. Check the wiring and voltages first, then buy a sensor if it tests bad.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.