AutoDiag

P0113

Intake Air Temperature Sensor 1 Circuit High (Bank 1)

Low· Fix when convenientDIY friendlyPowertrainGeneric, all makes

What it means

The intake air temperature (IAT) sensor signal voltage is above the normal range. The intake air temperature (IAT) sensor measures the temperature of the air entering the engine, which the ECU uses to fine-tune fuel and ignition timing. A high signal is usually caused by an open circuit (unplugged, broken wire), a missing ground or a short to voltage.

Is it safe to drive?

Safe to drive. The ECU uses a default value, so you may notice slightly worse economy or cold starts.

Symptoms

  • Check engine light on
  • Slight hesitation or rough running
  • Hard starting in cold weather
  • Reduced fuel economy

Probable causes

Most likely first

  1. 1Sensor unplugged or connector loose
  2. 2Open signal or ground wire (broken, corroded or pulled out of the connector)
  3. 3Failed sensor open internally (it reads extremely cold, often -40°)

How to diagnose it

Work through these in order before buying parts

  1. 1Record the code and its freeze frame data (speed, load, temperature when it set), then clear it and see if it comes back.
  2. 2Inspect the intake air temperature (IAT) sensor connector and wiring (in the air filter box, intake tube or built into the MAF sensor). Look for corrosion, bent or pushed-back pins, oil contamination and chafed insulation.
  3. 3Watch the intake air temperature (IAT) sensor reading on live data. After the car has sat overnight, IAT and coolant temperature should read within a few degrees of each other and of the outside temperature.
  4. 4Unplug the sensor and measure its resistance; it should drop smoothly as it warms up (compare with the chart in a service manual). With the key on, the ECU side of the connector should show about 5 volts on the signal wire and a good ground on the other.
  5. 5If the wiring checks out, test the sensor itself against the specification in a service manual.
  6. 6Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.

Common fixes

  • Repair the damaged wiring or connector
  • Replace the intake air temperature (IAT) sensor
  • Clear the code and test drive to confirm the repair

This information is general guidance for all makes. Exact causes, specifications and procedures vary by vehicle, so confirm with your service manual or a qualified mechanic before replacing parts.