DTC Advanced Diagnostics: P0099
DTC P0099:Intake Air Temperature (IAT) Sensor 2 Intermittent Interruption

General Description

An intermittent voltage signal check of the intake air temperature (IAT) sensor 2 is performed by comparing its raw voltage value with its low pass filtered voltage value. If the absolute difference between the IAT sensor voltage and the filtered voltage is a specified value, the powertrain control module (PCM) detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
1 second or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Engine coolant temperature [ECT Sensor 1]
139.93 °F (59.96 °C)
–
Intake air amount
–
24 kg/h (52 lbs/h)
Vehicle speed [Vehicle Speed]
–
6 mph (10 km/h)
Other
All conditions must be met at least 10 seconds
[ ]: HDS Parameter

Malfunction Threshold
The absolute difference between the IAT sensor 2 voltage and the filtered voltage is more than 0.8 V for at least 1 second.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes
IAT sensor 2 TA line short to power
IAT sensor 2 failure
PCM internal failure

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.