P0097

DTC P0097

CIRCUIT DESCRIPTION




This diagnostic monitors the signal of the intake air temperature (IAT) sensor. The IAT sensor is a variable resistor that measures the temperature of the intake air. The powertrain control module (PCM) supplies 5 volts to the IAT signal circuit and supplies a ground to the low reference circuit. If the PCM detects a low IAT signal voltage, which is a high temperature indication, this DTC sets.




The table illustrates the difference between temperature, resistance, and voltage:

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0097 Intake Air Temperature (IAT) Sensor 2 Circuit Low Voltage

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- DTC P0098 is not set.
- DTC P0097 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The PCM detects that the intake air temperature (IAT) sensor signal voltage is 0.08 volts or less.
- The above condition is present for at least 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The powertrain control module (PCM) illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
- Use the Temperature vs Resistance table in order to test the IAT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in a driveability condition. If the engine has sat overnight, the engine coolant temperature and the intake air temperature values should display within a few degrees. If the temperatures are not within 3°C (5°F), refer to Temperature vs Resistance - Intake Air Temperature (IAT) Sensor.
- An intermittent malfunction may be caused by a fault in the IAT sensor electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-9:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if a condition is present.
5. Disconnecting the PCM allows using the DMM in order to check continuity of the circuits. This aids in locating an open or a shorted circuit.
7. After replacing the PCM a new minimum throttle position and idle speed must also be established.