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Home >> Subaru >> 2017 >> WRX STI >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics - Introduction) (2.5L) >> Drive Cycle >> Procedure >> Drive Cycle H
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Drive Cycle H

DTC Item Condition
P0071 Ambient Air Temperature Sensor Circuit "A" Range/Performance
  • 6 hours have elapsed since ignition switch is OFF under a completely warmed up condition.
  • For models with block heater, at least 6 hours must have elapsed without operating the block heater.
P0116 Engine Coolant Temperature Sensor 1 Circuit Range/Performance
  • 6 hours have elapsed since ignition switch is OFF under a completely warmed up condition.
  • For models with block heater, at least 6 hours must have elapsed without operating the block heater.
P0451 Evap System (CPC) Pressure Sensor/Switch Circuit Range/Performance 60 seconds have elapsed since ignition switch is OFF.
P050A Cold Start Idle Control System Performance -
P050B Cold Start Ignition Timing Performance -
P2431 Secondary Air System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1 -

Diagnostic procedure: 

  1. With the ignition switch ON (engine stopped), read the value in «Coolant Temp.» and «Intake Air Temp.». <Ref. to DISPLAY CURRENT ENGINE DATA (NORMAL MODE) , OPERATION, Subaru Select Monitor.>
  2. If the values from step  1 satisfy the following conditions, idle the engine for two minutes or more.

    Condition: 

    |Engine coolant temperature - Intake air temperature| ≤ 5°C (9°F) 

    NOTE:
    • If the conditions are not satisfied, turn the ignition switch to OFF and wait until the parameters are satisfied.
    • Do not move the shift lever from neutral position during idling.
  3. Read the temporary code using the Subaru Select Monitor or general scan tool. <Ref. to OPERATION , Read Diagnostic Trouble Code (DTC).>