LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2021 >> WRX Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2.0L) - Introduction >> Drive Cycle >> Procedure >> Drive Cycle I
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Drive Cycle I

DTC Item Condition Number of driving cycles on the detecting condition
P0455 EVAP SYSTEM (CPC) LEAK DETECTED (LARGE LEAK) «Coolant Temp.»: 5 - 45°C (41 - 113°F) «IAT Sensor 5 - 50°C (41 - 122°F) 2
P0456 EVAP SYSTEM (CPC) LEAK DETECTED (VERY SMALL LEAK) 2
P04AF EVAP SYSTEM PURGE CONTROL VALVE (CPC) "B" STUCK CLOSED 2
P1451 EVAP SYSTEM CLOG DETECTED (PIPE) 2
P2402 EVAP SYSTEM LEAK DETECTION PUMP CONTROL CIRCUIT HIGH 1
P2404 EVAP SYSTEM LEAK DETECTION PUMP SENSE CIRCUIT RANGE/PERFORMANCE 2
P2420 EVAP SYSTEM SWITCHING VALVE CONTROL CIRCUIT HIGH 1
CAUTION: Be careful of the state of the battery when performing the drive cycle I consecutively. Performing the drive cycle I consecutively without the engine running may cause a low battery voltage and battery discharge.
NOTE:
  • If it is necessary to perform drive cycle I consecutively, drive the vehicle under the following conditions to release accumulated evaporating gas. Performing the drive cycle I consecutively without starting the engine causes a large amount of evaporating gas to accumulate in the canister, which hinders an accurate diagnosis.
  • After engine is warmed up
  • Drive for 10 minutes or more at a speed of 48 km/h (30 MPH) or more (duration of drive can be an accumulation)
  • To obtain an accurate diagnostic result, perform the procedures according to the following points.
  • Do not refuel gas immediately before performing drive cycle I. There will be a large amount of evaporating gas immediately after refuel, which may cause a less accurate diagnostic performance.
  • Do not shake the vehicle while performing drive cycle I. Shaking the vehicle causes evaporating gas to increase inside the fuel tank, which may cause a less accurate diagnostic performance.
  • Do not perform any service operation including installation or removal of parts or connectors while performing drive cycle I. Performing service operation could affect on the functions of related parts, which may cause a less accurate diagnostic performance.
  • Perform MODE $08 when using a general scan tool.
  1. Prepare the Subaru Select Monitor 4. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>GENERAL DESCRIPTION>PREPARATION TOOL .
  2. Prepare PC with Subaru Select Monitor installed.
  3. Connect the USB cable to the DST-i and the USB port on the personal computer (dedicated port for the Subaru Select Monitor).
    NOTE: The dedicated port for the Subaru Select Monitor means the USB port which was used to install the Subaru Select Monitor.
  4. Connect the diagnosis cable to DST-i.
  5. Connect the DST-i to the data link connector located in the lower portion of the instrument panel (on the driver's side).
    CAUTION: Do not connect the scan tools except for Subaru Select Monitor and general scan tool.
    G08315883Courtesy of SUBARU OF AMERICA, INC.
  6. Start the PC.
  7. Turn the ignition switch to ON (engine OFF) and run the "PC application for Subaru Select Monitor".
  8. On «Start» display, select «OBD System».
  9. On «Select System» display, select «Evaporative System Leak Test».
  10. On «Evaporative System Leak Test» display, select «Evaporative System Leak Test».
  11. On «Evaporative System Leak Test is running. Press Cancel to exit this function.» display, click the «OK» button to perform evaporative system leak test.
  12. When «Conditions have been enabled to control this function. Turn the ignition switch off to terminate the test.» display appears, wait for 30 minutes without clicking the «OK» button.
    CAUTION: Do not leave the vehicle for an extended period of time after the test is complete. This may cause early deterioration of the battery or discharged battery.
    NOTE:
    • Clicking the «OK» button bring the «Evaporative System Leak Test» display back, although the test is continuing.
    • The Subaru Select Monitor screen does not change after the evaporative system leak test is complete or when the test is aborted by turning off the ignition switch.
    • If «Test conditions are not correct» display appears, use Subaru Select Monitor to check that the values in «Coolant Temp.» and «IAT Sensor are within the specified range. If the conditions are satisfied, make the necessary preparation for the drive cycle again. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>DRIVE CYCLE>PROCEDURE>PREPARATION FOR DRIVE CYCLE .
  13. After 30 minutes passed from the start of step 14), click the «OK» button to return to the «Evaporative System Leak Test» display.
  14. Return to the «OBD System» display, then select «On-board monitor test result».
  15. In the «On-board monitor test result», check TID $C1 -$CA of MID $3C.
    NOTE: Perform MODE $06 and check when using a general scan tool.
    RESULT OF ON-BOARD MONITOR TEST

    Display Details Remarks
    $0000 is stored in all Val. During the evaporative system leak test, the test conditions were not met and the test was canceled. Once the test conditions are met, perform the test again.
    All Val. are stored with values and OK is set to all the results. Evaporative system leak test is completed correctly. While the ignition switch is ON, read the pending code using the Subaru Select Monitor.
    Some results were no good. The evaporative system leak test completed successfully but the results were faulty. While the ignition switch is ON, read the pending code using the Subaru Select Monitor.
  16. When the evaporative system leak test is completed correctly, read the pending code with the ignition switch turned to ON position. If the DTC is recorded, check the appropriate DTC. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>READ DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .
    NOTE:
    • Perform MODE $07 when using a general scan tool.
    • The pending code will be cleared by turning ignition switch to OFF.
scientia non olet · About LEMON Manuals