P1111

Description
IAT SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE

Intake Air Temperature (IAT) sensor is a thermistor. PCM
applies and reads a 5-volt reference signal to sensor. When air is
cold, sensor resistance is high and PCM will measure a high signal
voltage. If air is warm, sensor resistance is low causing PCM to
measure low voltage.
Symptoms
You likely won't notice any drivability problems.

Causes

• IAT intermittently less than -38F (-39C).

Possible Solutions

• If DTC P0113 is also set, diagnose DTC P0113 before
  proceeding.
• Check for faulty sensor ground circuit terminal at IAT
  sensor.
• Check for faulty signal circuit connection at IAT sensor.
  Repair as necessary.
• Check for intermittent open or faulty splice in sensor
  ground circuit.
• Check for faulty connections or damaged harness.
• Replace IAT sensor.