Operation CHARM: Car repair manuals for everyone.

Advanced Diagnostics

Advanced Diagnostics - 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, OBD Status






Enable Conditions






Malfunction Threshold
The total airflow is decreased by a factor of 0.55 for at least 10 seconds.

Driving Pattern
1. Allow the engine to cool to an engine coolant temperature of 131 °F (55 °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 battery.