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DTC P050A: Cold Start Idle Air Control System Performance [05/2013 - 01/2014]: Description

This monitor will run when the engine is started with the engine coolant temperature between -10 and 50°C (14 and 122°F). The DTC will be stored after the engine idles for 13 seconds (2 trip detection logic).

The DTC is designed to monitor the idle air control at cold start. When the engine is started with the engine coolant temperature below 50°C (122°F), the ECM measures the accumulated mass air flow while the engine is idling. If it does not reach the threshold within 10 seconds, the ECM interprets this as a malfunction. The MIL is illuminated and a DTC is stored when the malfunction is detected in consecutive driving cycles (2 trip detection logic).

The ETCS (Electronic Throttle Control System) controls the idle speed. The ETCS operates the throttle actuator to open and close the throttle valve, and adjusts the intake air amount to achieve the target idle speed.

NOTE:

When the cable is disconnected from the negative battery terminal during inspections or repairs, the ISC (Idle Speed Control) learned values are cleared. This DTC cannot be stored with the ISC learned values cleared.

HINT: 

ISC learning is performed when the engine is warmed up and has been idling for 5 minutes.

Fig 1: Identifying Cold Start Idle Air Control System Performance Graph
GTY422131Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DTC No. DTC Detection Condition Trouble Area
P050A Insufficient mass air flow after a cold start (2 trip detection logic).
  • Throttle with motor body assembly
  • Mass air flow meter sub-assembly
  • PCV hose
  • Air cleaner filter element sub-assembly
  • Air induction system
  • VVT system
  • ECM
  • Wire harness or connector