Engine Management

Scan Tool 57 (MIL 23):

Trouble Code Number
- Scan tool 57
- General scan tool P0112
- MIL 23

Fault Message
- Intake Air Temperature Sensor Voltage Low

Background
- When the fuel system is in the open loop mode, the heated oxygen sensor cannot be used for injector pulse width calculation.
- In this instance, the system uses information on air mass to determine the correct pulse width necessary to achieve the proper air/fuel ratio.
- Because air mass is related to temperature, information from the intake air temperature sensor is necessary.

Range of Check
- Ignition switch: ON

Set Condition
- Intake air temperature sensor output voltage is less than 0.2 V for 3 seconds.

Probable Cause
- Sensor signal shorted to ground
- Sensor internally shorted
- PCM failed