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.
2009 Lexus IS 250 AWDFACTORY OEM SERVICE PROCEDURE
System Diagram
COMMUNICATION TABLE:
| Transmitting ECU (Transmitter) |
Receiving ECU (Receiver) |
Signal | Communication method |
|---|---|---|---|
| ECM | Power source control ECU | Engine rotation signal | CAN/BEAN |
| Meter ECU | Power source control ECU | Vehicle speed signal | BEAN/Local communication |
| Steering lock ECU | Power source control ECU | Steering lock/unlock signal | LIN/Local communication |
| Shift lock control ECU | Power source control ECU | Shift position signal | BEAN/Local communication |
| Certification ECU | Power source control ECU | LIN master signal | LIN |
| Power source control ECU | Certification ECU | ID required signal | LIN |
| Key existence condition signal | BEAN |
Factory Service Tools
Use the Manual With the Right Hardware
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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.