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Home >> Subaru >> 2019 >> BRZ Series.Gray >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2 Of 3) >> EFI System (FA20) >> DTC P050A: Cold Start Idle Air Control System Performance; DTC P050B: Cold Start Ignition Timing Abnormal >> Circuit description >> Notes
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Circuit description: Notes

The Cold Start Emission Reduction Strategy (CSERS), which shortens the time necessary for the catalyst to warm up after cold start, is used in this vehicle. The CSERS consists of related ignition timing and increased engine idle speed in calibrated time.

This monitor detects estimated exhaust gas temperature which has not reached the target value, ignition timing from the ECM, and engine idle speed failure.

DTC No. DTC detection conditions Suspected parts
P050A From the cold engine condition, the engine speed not reach the target engine speed within 7 seconds. (2 trips detection logic)  
  • Throttle body
  • Intake air flow meter SUB-ASSY
  • PCV system
  • Air cleaner filter element
  • Intake system
  • VVT system
  • Wiring harness or connector
  • ECM
P050B Despite abrupt warming control of the catalyst, ignition timing is not retarded for 7 seconds (to delay ignition timing). (2 trips detection logic)
MONITOR STRATEGY

Related DTCs P050A: Cold start emission reduction strategy functional check
P050B: Cold start emission reduction strategy functional check
Required Sensors/Components (Main) Throttle body
Required Sensors/Components (Related) Intake air flow meter SUB-ASSY
Vacuum sensor
E.F.I. water temperature sensor
Frequency of Operation Once per driving cycle
Duration 7 seconds
MIL Operation 2 operation cycle
Sequence of Operation None