Fuel and air

P00E9 — Intake Air Temperature Sensor 3 Circuit Range/Performance (Bank 1)

Severity: medium Drive with care, to a shop

What P00E9 means

The engine control module compares the signal from intake air temperature sensor 3 on bank 1 with expected values and with other temperature sensors. If the reading is stuck, erratic or doesn't fit the conditions, it sets P00E9. Air temperature is used to calculate air density and therefore how much fuel to inject.

Symptoms

  • Check Engine light on
  • Rough idle
  • Poor fuel economy
  • Hesitation or stumbling when accelerating
  • Unrealistic air temperature readings on a scan tool

Possible causes

  1. Failed intake air temperature sensor
  2. Poor connection, corrosion or break in the sensor wiring or connector
  3. Signal wire shorted to ground or to power
  4. Vacuum leak or intake duct problem skewing readings
  5. Faulty engine control module (rare)

How to diagnose

  1. Read all codes and freeze frame data and look for other temperature or airflow codes
  2. With a cold engine, compare this sensor's reading with other air temperature sensors and with coolant temperature on a scan tool
  3. Inspect the connector and harness for corrosion, chafing, heat damage and loose terminals
  4. Check the intake tract for vacuum leaks and damaged ducts
  5. Measure the sensor resistance and compare it to the manufacturer's chart at a known temperature
  6. Test the reference voltage, signal wire and ground for opens and shorts
  7. If wiring and sensor are good, check the ECM and for software updates

Common fixes

  • Replace the intake air temperature sensor
  • Repair or replace damaged wiring or the connector
  • Fix vacuum leaks or intake tract faults
  • Repair or replace the ECM (last resort)

Questions and answers

What does P00E9 mean?

The ECM sees a signal from intake air temperature sensor 3 (bank 1) that is out of range or disagrees with other sensors. The sensor or its connector is the most common culprit.

Can I drive with a P00E9 code?

Usually yes for short trips until it's repaired. You may notice hesitation, rough idle and higher fuel use, so get it diagnosed soon.

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.