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.
1997 Lexus LS 400FACTORY OEM SERVICE PROCEDURE
Multiplex Control System
- Description & Operation
- Self-Diagnostics
- Testing
- Test No. 1: Driver's Door Ecu Communication Circuit
- Test No. 2: Front Passenger's Door Ecu Communication Circuit
- Test No. 3: Tilt/Telescopic Ecu Communication Circuit
- Test No. 4: Communication Circuit
- Test No. 5: Power Window Master Switch Circuit
- Test No. 6: Driver's Door Switch Circuit
- Test No. 7: Front Passenger Door Lock Control Switch & Door Key Lock & Unlock Switch
- Test No. 8: Luggage Compartment Door Opener Switch Circuit, Luggage Compartment Door Key Operated Switch Circuit, Wireless Door Lock Ecu Circuit
- Test No. 9: Power Mirror Control Switch Circuit
- Pin Voltage Tests
- Notes
- Body Ecu
- Driver's Door Ecu
- Notes
- A2 & C10
- A3 & C10
- A5 & C10
- A6 & C10
- A10 & C14
- A12 & C10
- A15 & C10
- B2 & C10
- B3 & C10
- B4 & C10
- B5 & C10
- B6 & C10
- B7 & C10
- B8 & C10
- B10 & C10
- B11 & C10
- B12 & C10
- B13 & C10
- B14 & C10
- B15 & C10
- C1 & C10
- C2 & C10
- C3 & C10
- C4 & C10
- C5 & C10
- C6 & C10
- C7 & C10
- C8 & C10
- C9 & C10
- C10 & C11
- C10 & C12
- C10 & C13
- C10 & Ground
- C11 & Ground
- C10 & C16
- C10 & C17
- C10 & C18
- Front Passenger's Door Ecu
- Wiring Diagrams
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.
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