2019 Subaru Ascent BaseFACTORY OEM SERVICE PROCEDURE

Diagnostic Method

Judge as NG if the criteria below are met.

Judgment value

JUDGMENT VALUE SPECIFICATION (1)

Malfunction Criteria Threshold Value
Throttle minimum stop position 2.2 V or more
JUDGMENT VALUE SPECIFICATION (2)

Malfunction Criteria Threshold Value
Accelerator pedal position learning value in backup RAM area 1 Not equal to accelerator pedal position learning value in backup RAM area 2
JUDGMENT VALUE SPECIFICATION (3)

Malfunction Criteria Threshold Value
Total of backup RAM (ECM shutdown) Not equal to total of backup RAM (ECM startup)
JUDGMENT VALUE SPECIFICATION (4)

Malfunction Criteria Threshold Value
Communication status between main CPU and sub CPU Malfunction
JUDGMENT VALUE SPECIFICATION (5)

Malfunction Criteria Threshold Value
Throttle control calculation data by main CPU Not equal to throttle control calculation data by sub CPU
JUDGMENT VALUE SPECIFICATION (6)

Malfunction Criteria Threshold Value
Calculation data by main CPU Not equal to calculation data by FPU
JUDGMENT VALUE SPECIFICATION (7)

Malfunction Criteria Threshold Value
Actual engine output - Target engine output More than 20 kw (27 PS)

Time needed for diagnosis.Β 

  • Judgment 1, 2, 3, 4, 5: Less than 1 s
  • Judgment 6: 200 ms
  • Judgment 7: 500 ms

Malfunction indicator light illumination:Β  Illuminates as soon as a malfunction occurs.

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:

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

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