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.
Diagnostic Method
- Abnormality Judgment
Judge as NG when the malfunction criteria below are met.
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Main CPU normal RAM abnormal | |
| Write 5AA5A55A and then read. (Whole area of RAM) | 5AA5A55A cannot be read. |
| Write A55A5AA5 and then read. (Whole area of RAM) | A55A5AA5 cannot be read. |
| Sub CPU normal RAM abnormal | |
| Write 5AA5 and then read. (Whole area of RAM) | 5AA5 cannot be read. |
| Write A55A and then read. (Whole area of RAM) | A55A cannot be read. |
Time Needed for Diagnosis: 100 milliseconds
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
- Normality Judgment
Judge as OK and clear the NG when the malfunction criteria below are met.
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Main CPU normal RAM abnormal | |
| Write 5AA5A55A and then read. (Whole area of RAM) | 5AA5A55A can be read. |
| And write A55A5AA5 and then read. (Whole area of RAM) | A55A5AA5 can be read. |
| Sub CPU normal RAM abnormal | |
| Write 5AA5 and then read. (Whole area of RAM) | 5AA5 can be read. |
| And write A55A and then read. (Whole area of RAM) | A55A can be read. |
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.