Intake air temperature (IAT) sensor codes

How its codes differ

• P0113 means the IAT signal is at the high-voltage end, which the computer reads as impossibly cold air: usually an open circuit, unplugged connector or failed sensor rather than a real temperature.
• When the IAT is built into the MAF housing, P0113 together with P0101 or P0102 points to a shared connector or wiring fault.

Codes

• P0113

  The intake air temperature signal is stuck at a reading colder than any real air could be

  Severity: Monitor

• P0101

  Airflow sensor reading doesn't match what the engine computer expects for the throttle opening

  Severity: Inspect soon

• P0102

  The airflow sensor's signal is lower than the engine computer will accept

  Severity: Inspect soon

Signs it's failing

• Check engine light with P0113
• Hard starting, especially in the cold
• Reduced power or hesitation
• Higher fuel use

How to test it

1. With the engine cold, compare the IAT reading on a scan tool with the outside air temperature; a reading far below any real temperature fits P0113. (Low risk)

2. With the engine off, check the sensor connector for corrosion, damage or a loose fit. (Low risk)

3. Resistance and supply-voltage tests against specification need a meter and service information; have a shop do them if unsure. (Use caution)

   Warning: Work with the ignition off when probing connectors unless the test calls for it, and avoid shorting terminals.

After the repair

• Check that the IAT reading matches outside air on a cold engine.
• Clear codes only after the repair, then drive normally over several days with both city and highway driving so the readiness monitors can complete; clearing codes or disconnecting the battery resets them to not ready, which fails an emissions test.