2018 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE

Drive Cycle Q

DTC Item Condition
P0191 FUEL RAIL PRESSURE SENSOR CIRCUIT RANGE/PERFORMANCE BANK 1
  • With the ignition switch ON (engine stopped), read the value in «Coolant Temp.».
  • If the engine coolant temperature meets the condition of = 30°C, idle the engine for 30 minutes or more.
  • If the engine coolant temperature does not meet the condition of = 30°C, start the engine, wait until the engine coolant temperature meets the condition of = 30°C, turn OFF the ignition switch once, then idle the engine for 30 minutes or more.
  • At least 6 hours must have elapsed since ignition switch was OFF.
  • For models with block heater, at least 6 hours must have elapsed without operating the block heater.

Diagnostic procedure: 

  1. Idle the engine for at least one minute.
    NOTE: For CVT models, hold the select lever to "P" range or "N" range at idling, and for MT models, the gear shift lever in the neutral position at idling.
  2. Read the temporary code using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Read Diagnostic Trouble Code (DTC)>OPERATION .
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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