DTC P050A: Cold Start Idle Air Control System Performance [08/2017 - 08/2018]: Description

WARNING: This page is about a different car, the 2018 Toyota Sequoia, 2017 Toyota Sequoia, and 2016 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

This monitor will run when the engine is started with the engine coolant temperature at -10 to 50°C (14 to 122°F). The DTC will be set 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 at lower than 50°C (122°F), the ECM (PCM) measures the accumulated mass air flow at engine idling. If it does not reach the criteria within 10 seconds, the ECM (PCM) interprets this as a malfunction. The MIL is illuminated and a DTC is set 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 negative battery terminal is disconnected during inspections or repairs, the ISC (Idle Speed Control) learning values are cleared. This DTC cannot be set with the ISC learning values cleared.

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

DTC Code	DTC Detection Condition	Trouble Area
P050A	Insufficient mass air flow at cold start (2 trip detection logic)	Throttle body assembly Mass air flow meter PCV hose Air cleaner filter element sub-assembly Air induction system VVT system ECM Wire harness or connector