Fuel and air

P00A8 — Intake Air Temperature Sensor 2 Circuit High (Bank 2)

Severity: medium Safe to drive

What P00A8 means

The engine control module monitors the signal voltage from intake air temperature sensor 2 (IAT2) on bank 2. The sensor is a thermistor: colder air means higher resistance and higher signal voltage. P00A8 sets when the voltage stays above the allowed limit, so the module sees an unrealistically cold reading. This usually points to an open circuit, a poor connection or a failed sensor.

Symptoms

  • Check Engine light on
  • IAT2 reads an unrealistic value in live data (often around -40°F/°C)
  • Rough idle
  • Sluggish acceleration
  • Higher fuel consumption
  • Harder cold starts in some cases

Possible causes

  1. Failed IAT2 sensor
  2. Open circuit in the signal or ground wire
  3. Corroded, bent or loose connector pins
  4. Signal wire shorted to voltage
  5. Rarely, a faulty engine control module

How to diagnose

  1. Scan for codes and freeze frame data, and look for related IAT or MAF codes
  2. Compare IAT2 with IAT1 on a cold engine; both should be close to ambient temperature
  3. Inspect the sensor connector and harness for corrosion, chafing or damage
  4. Unplug the sensor and jumper signal to ground: the reading should drop toward a hot value, otherwise suspect an open circuit
  5. Check the reference voltage (about 5 V) and the ground wire with a multimeter
  6. Measure sensor resistance and compare it with the spec at a known temperature
  7. Test the signal wire to the module for opens and shorts to voltage

Common fixes

  • Replace the IAT2 sensor
  • Repair damaged wiring or replace the connector
  • Fix the short to voltage or the open in the circuit
  • Clean the terminals and secure the connector
  • As a last resort, check, reflash or replace the control module

Questions and answers

What does P00A8 mean?

It means the bank 2 intake air temperature sensor 2 circuit is sending a high voltage signal. The most common causes are an open circuit or a bad sensor.

Can I drive with P00A8?

For a short time, yes, but fuel economy, performance and emissions can get worse. Have the sensor and wiring checked soon.

How do I quickly test IAT2?

Compare its reading with IAT1 on a cold engine. If IAT2 shows an extremely cold value, check the connector, wiring and the sensor itself.

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.