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Home >> Mercury >> 2009 >> Mariner Base, 2.5 7, AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Powertrain DTC Charts & Descriptions (Except Diesel & Hybrid) >> DTC Diagnosis >> DTC P050A: - Cold Start Idle Air Control Performance

DTC P050A: - Cold Start Idle Air Control Performance

DTC P050A: - COLD START IDLE AIR CONTROL PERFORMANCE

Description:  The cold start emission reduction monitor has detected an airflow performance deficiency. The cold start emission reduction monitor validates the operation of the components of the system required to achieve the cold start emission reduction strategy, retarded spark timing (P050B) and elevated idle airflow (P050A). When the idle airflow test portion of the cold start emission reduction strategy is enabled, the idle air control system requests a higher idle RPM to increase the engine airflow. The cold start emission reduction monitor compares the actual airflow measured by the mass air flow (MAF) sensor to the requested powertrain control module (PCM) airflow. The DTC sets when the airflow is less than the calibrated limit.
Possible Causes: 
  • Damaged intake air system tubes
  • Restricted air filter
  • Restricted or blocked idle air control or intake passages
  • Air or vacuum leaks
  • Base engine problem
Diagnostic Aids:  This DTC is an informational DTC and may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present inspect the intake air system for air restrictions and damage. If no concerns are present, clear the DTCs and repeat the self-test.
The cold start emission reduction monitor runs during a cold start. Before repeating the self-test, a 2 to 3 hour soak period is required for the cold start emission reduction monitor to run at start up.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.