P0098

DTC P0098 Intake Air Temperature (IAT) Sensor Circuit 2 High Voltage

Circuit Description

The intake air temperature (IAT) sensor 2 is installed to the intake manifold. The IAT sensor 2 is a variable resistor and it measures the temperature of the air entering the engine that mixed with EGR gas. The sensor has a signal circuit and a low reference circuit. The ECM supplies 5 volts to the signal circuit and a ground for the low reference circuit. When the IAT sensor 2 is cold the sensor resistance is high. When the EGR gas flow amount increases and thus intake air temperature increases the sensor resistance decreases. With higher sensor resistance the ECM detects a high voltage on the signal circuit. With lower sensor resistance the ECM detects a lower voltage on the signal circuit. If the ECM detects an excessively high signal voltage this DTC will set.

Condition for Running the DTC

^ DTC P0097 P0112 and P0113 are not set.
^ The battery voltage is between 10 to 16 volts.
^ The ignition switch is ON.
^ The engine runtime is longer than 7 minutes.
^ The engine speed is more than 1600 RPM.
^ The fuel injection quantity is more than 40 mm3.

Condition for Setting the DTC

^ The ECM detects that the IAT sensor 2 signal voltage is more than 4.9 volts for 2 seconds.

Action Taken When the DTC Sets

^ The ECM illuminates the MIL when the diagnostic runs and fails. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type A.

Condition for Clearing the DTC

^ Refer to DTC Type Definitions for Condition for Clearing the MIL/DTC - Type A.

Diagnostic Aids

^ If an intermittent condition is suspected refer to intermittent conditions in this section.
^ Use the Temperature vs. Resistance table to test the IAT sensor 2 at various temperature levels to evaluate the possibility of a skewed sensor.

Circuit System Testing DTC P0098