Fuel and air

P0113 — Intake Air Temperature Sensor Circuit High Input

Severity: low Safe to drive

What P0113 means

The engine computer detected a voltage from the intake air temperature (IAT) sensor that is higher than expected. The sensor is a thermistor: colder air means higher resistance and higher signal voltage. An excessively high reading usually points to an open circuit, a lost ground or a failed sensor. The computer uses air temperature to adjust fueling and timing, so the mixture can be off.

Symptoms

  • Check Engine light on
  • Poor fuel economy
  • Rough idle or hesitation
  • Hard starting, especially when cold
  • Uneven running when warm
  • Skewed fuel trims

Possible causes

  1. Failed intake air temperature sensor
  2. Open circuit, corrosion or a bad connector in the sensor wiring
  3. Signal wire shorted to voltage
  4. Open or poor sensor ground wire
  5. Failed combined MAF/IAT sensor assembly
  6. Faulty PCM (rare)

How to diagnose

  1. Scan for codes and freeze frame data, and note any MAF or manifold pressure codes
  2. Read the IAT value on a scan tool: on a cold engine it should be near ambient, and a reading around -40°F/°C suggests an open circuit
  3. Inspect the sensor connector and harness for corrosion, chafing or a loose lock
  4. Unplug the sensor and jumper the signal and ground terminals: the reading should swing to a very high temperature, otherwise the wiring has an open
  5. Use a multimeter to check for 5 V reference and a good ground back to the PCM
  6. Measure sensor resistance and compare it to the spec chart for that vehicle at a known temperature
  7. Check the wiring between sensor and PCM for opens and shorts to voltage

Common fixes

  • Replace the IAT sensor
  • Repair the wiring or replace the connector and clean the terminals
  • Replace the MAF sensor assembly if the IAT is built in
  • Repair or reprogram the PCM only after everything else is ruled out

Questions and answers

Can I drive with a P0113 code?

Usually yes, for short trips. The engine may run roughly and use more fuel, so get it diagnosed soon.

What most often causes P0113?

Most often a failed IAT sensor or a bad connection or open wire in its circuit. Start by inspecting the connector and checking the sensor reading on a scan tool.

Can I just clear the code?

You can, but it will return if the cause is still there. Find the open circuit or faulty sensor first.

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.