Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Subaru WRX STIFACTORY OEM SERVICE PROCEDURE
Execution Condition
EXECUTION CONDITION (JUDGMENT 1 - INSTRUCTION)
| Secondary parameters | Execution condition |
|---|---|
| Initial routine Main CPU |
Execution in progress |
EXECUTION CONDITION (JUDGMENT 1 - INSTRUCTION)
| Secondary parameters | Execution condition |
|---|---|
| Ignition switch | ON |
| Battery voltage | ≥6.2V |
| Electronic throttle control relay | ON |
EXECUTION CONDITION (JUDGMENT 2 - SOFT FLOW)
| Secondary parameters | Execution condition |
|---|---|
| (2) Ignition switch | ON |
EXECUTION CONDITION (JUDGMENT 3 - SOFT MONITOR)
| Secondary parameters | Execution condition |
|---|---|
| Ignition switch | ON |
| Battery voltage | ≥6.2V |
| Electronic throttle control relay | ON |
EXECUTION CONDITION (JUDGMENT 4 - IF OUTPUT IC OPERATION IS ABNORMAL)
| Secondary parameters | Execution condition |
|---|---|
| Ignition switch | ON |
EXECUTION CONDITION (JUDGMENT 5 - CAN REGISTER)
| Secondary parameters | Execution condition |
|---|---|
| (5) Initial routine | Execution in progress |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.