P2199

DTC P2199

DESCRIPTION
The DTC P2199 Intake Air Temperature (IAT) Sensor 1/2 Correlation diagnostic compares the IAT sensor 1 input with the IAT sensor 2 input. There are two IAT sensors on the 3.5L engine. IAT sensor 1 is located in the intake air duct and IAT sensor 2 is located in the intake manifold. The IAT sensor is a thermistor. A thermistor is a resistor whose value varies with temperature. The IAT sensors resistance is high when the coolant temperature is cold, and the IAT sensors resistance is low when the coolant temperature is warm.

The IAT sensor is wired in series with a fixed resistor in the powertrain control module (PCM). The PCM applies 5 volts to the IAT sensor. The PCM monitors the voltage across the IAT sensor and converts the voltage into a temperature reading. The PCM expects the output of the two IAT sensors to follow the same linear path. If the two sensors report conflicting information to the PCM a DTC P2199 can set.

DTC DESCRIPTOR
This diagnostic supports the following DTC.
P2199 Intake Air temperature (IAT) Sensor 1/2 Correlation.




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

CONDITIONS FOR RUNNING THE DTC
- DTCs P0097, P0098, and P2610 are not set.
- The ignition is ON.
- The engine has been OFF for at least 8 hours.
- DTC P2199 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
- The temperature difference between IAT sensor 1 and IAT sensor 2 is 25°C (77°F) or more.
- The above condition is present for at least 7 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic fails.
- The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

CONDITIONS FOR CLEARING THE MIL/DTC
- The PCM turns OFF the MIL after 3 consecutive trips without a fault.
- The PCM clears a History DTC after 40 consecutive warm-up cycles without a fault.
- Use the scan tool Clear DTC Information function.

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.
7. After replacing the PCM a new minimum throttle position and idle speed must also be established.