Fuel and air

P0114 — Intake Air Temperature (IAT) Sensor Circuit Intermittent

Severity: low Safe to drive

What P0114 means

The engine computer constantly reads a voltage from the intake air temperature (IAT) sensor, whose resistance changes with air temperature. P0114 sets when that signal drops out, jumps around, or changes in a way that doesn't make physical sense. The ECU uses this data to work out air density, fuel delivery and ignition timing.

Symptoms

  • Check Engine light on
  • Worse fuel economy
  • Rough idle or hesitation on acceleration
  • Hard starting, hot or cold
  • Erratic engine performance or surging

Possible causes

  1. Failing IAT sensor with an intermittent internal fault
  2. Damaged or corroded sensor wiring, chafed harness
  3. Loose or corroded connector at the sensor or ECU
  4. Faulty mass air flow (MAF) sensor when the IAT is built into it
  5. Rarely, an ECU software or internal fault

How to diagnose

  1. Scan for codes and watch live IAT data for jumps or dropouts.
  2. On a cold engine, compare IAT with ambient temperature; they should be close.
  3. Inspect the sensor connector for moisture, corrosion, loose locks and bent pins.
  4. Wiggle the harness and connector with the engine running while watching the reading; a jump points to a bad connection.
  5. Measure sensor resistance and compare with the spec chart, then warm it gently and recheck.
  6. Test the signal and ground wires back to the ECU for opens, shorts and high resistance.
  7. Check for 5 V reference voltage at the sensor connector.
  8. If the IAT is part of the MAF sensor, test the MAF as well.

Common fixes

  • Clean the connector terminals or replace a damaged connector
  • Repair or replace damaged wiring
  • Replace the IAT sensor
  • Replace the MAF sensor if it contains the faulty IAT
  • Reflash or replace the ECU only after ruling out everything else

Questions and answers

Can I drive with a P0114 code?

Usually yes, for short trips until it's fixed. The engine runs on fallback values, so expect poorer economy and response. Don't put the repair off for long.

How do I tell a bad IAT sensor from a wiring problem?

If the reading jumps when you wiggle the harness or connector, it's a connection or wiring fault. If the wiring and reference voltage are fine but the sensor's resistance doesn't match spec, replace the 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.