Fuel and air

P00EA — Intake Air Temperature Sensor 3 Circuit Low (Bank 1)

Severity: medium Drive with care, to a shop

What P00EA means

The engine control module detected that the signal voltage from intake air temperature sensor 3 (bank 1) is below the expected range. The sensor is a thermistor: the module feeds it a 5 V reference and reads the voltage drop to work out air temperature. A very low voltage looks like extremely hot air or a short to ground in the circuit.

Symptoms

  • Check engine light on
  • Rough idle
  • Poor fuel economy
  • Sluggish acceleration or loss of power
  • Hard starting (not always)
  • Occasional misfires

Possible causes

  1. Failed intake air temperature sensor 3
  2. Signal wire shorted to ground
  3. Chafed or damaged wiring harness insulation
  4. Corroded or loose connector terminals
  5. Water or oil in the sensor connector
  6. Reference voltage fault or ECM failure (rare)

How to diagnose

  1. Scan for codes and freeze frame data, and note any other air temperature or boost sensor codes
  2. Locate sensor 3 on bank 1 using the wiring diagram and inspect its connector and harness for chafing, moisture and corrosion
  3. On a cold engine, compare the scan tool IAT3 reading with actual ambient temperature; they should be close
  4. Unplug the sensor: if the reading goes to the coldest value or the code changes to an open circuit, the sensor or its wiring was the cause; if the low reading stays, look for a short in the harness
  5. Check for 5 V reference at the connector with a multimeter
  6. Test the signal wire for a short to ground and for continuity to the ECM
  7. Measure sensor resistance and compare it with the spec at a known temperature
  8. Clear the code and see whether it returns

Common fixes

  • Replace intake air temperature sensor 3
  • Repair or replace the damaged section of wiring
  • Clean or replace corroded connector and terminals
  • Fix the source of moisture getting into the connector
  • If the reference voltage is faulty, diagnose and repair the ECM or its supply

Questions and answers

Can I drive with P00EA?

Usually yes for short trips, because the ECM uses a default temperature value. Performance and fuel economy may suffer, so have it diagnosed soon.

What does a low circuit code on an air temperature sensor mean?

The signal voltage is lower than normal, which happens with a short to ground or a failed sensor. The ECM then thinks the air is extremely hot.

Will replacing the sensor fix it?

Not always. Check the connector and wiring first, because a shorted harness will keep the code coming back even with a new sensor.

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.