Questions and Answers

Saturn DTC P0112 Q. I have a 2000 Saturn 2.2 liter and the Check Engine Light comes on all the time. I used my diagnostic scanner tool and it give me a code P0112, I checked and clean the throttle and also replaced my air filter. I also remove the code and road tested, but still the find that the check engine light come back on and the code P0112 comeback.

I will like to now if you can help me? But giving me some more test I can do or if they have recalls for that.

A. P0112 Intake Air Temperature Circuit Low Input.

The Intake Air Temperature (IAT) sensor is a thermistor located in the air intake passage of the air induction system on the engine. When the sensor is cold it has a high resistance the resistance decreases as the temperature of the sensor increases. The PCM supplies a 5 volt signal to the sensor which is also connected to ground. The PCM reads the voltage drop on the sensor signal line to determine air temperature.

DTC PARAMETERS
DTC P0112 will set if the IAT reading is greater than 128°C (262°F) for 3.125 seconds and when:

• Engine run time is greater than 320 seconds .
• Vehicle speed greater than 24 km/h (15 mph) .
• DTCs P0117, P0118, P0125, P0502 and P0503 are not set.

IMPORTANT: The IAT signal is continuously checked when ignition is ON.

DIAGNOSTIC AIDS

• IAT may be compared to ECT temperature, with a Scan tool, if engine has been cooled overnight at ambient temperature. They should be relatively close to each other with ignition On and engine Off.