DTC Advanced Diagnostics: P050A
DTC P050A:Cold Start Idle Air Control System Performance Problem

General Description
The quick warm-up system supplies additional air and retards the ignition timing when the engine is cold to activate the catalytic converter as quickly as possible. When the actual amount of air is less than the target amount, the powertrain control module (PCM) detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Once per driving cycle
Sequence
None
Duration
10 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
Duration of quick warm-up system operation after engine start-up
–
40 seconds
Engine coolant temperature [ECT SENSOR 1]
50 °F (10 °C)
122 °F (50 °C)
Throttle position
Fully closed
Other
Vehicle stopped
[ ]: HDS Parameter

Malfunction Threshold
The total airflow is decreased by a factor of 0.42*1 (0.39)*2 for at least 10 seconds.

*1: L15B7 (except Si)
*2: Si

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.
Intake air duct breakage
Intake air duct misinstalled
Air cleaner breakage
Air cleaner damage
Air cleaner clogged
Mass airflow (MAF) sensor failure
Intake air system clogged
Intake air temperature (IAT) sensor 1 failure
Engine coolant temperature (ECT) sensor 1 failure
Ignition system failure

Confirmation Procedure
Operating Condition
1.
Allow the engine to cool to an ambient engine coolant temperature [ECT SENSOR 1] of 122 °F (50 °C) or less.
2.
Start the engine, and let it idle for at least 10 seconds.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, 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 or by disconnecting the 12 volt battery.