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
Test No. 4: Communication Circuit
- Disconnect tilt/telescopic ECU connectors. Connect jumper wire between DLC2 terminal E1 and terminal Tc. See Figure. Turn ignition on. Check open door indicator light for any trouble codes. If Codes 14 and 15 are present, go to next step. If no codes are present, check tilt/telescopic ECU. See STEERING COLUMN - POWER TILT SYSTEM article.
- Disconnect driver's door ECU connectors. Connect jumper wire between DLC2 terminal E1 and terminal Tc. See Figure. Turn ignition on. Check open door indicator light for any trouble codes. If Codes 14 and 15 are present, go to next step. If no codes are present, check driver's door ECU. See DRIVER'S DOOR ECU under PIN VOLTAGE TESTS.
- Disconnect front passenger's door ECU connectors. Connect jumper wire between DLC2 terminal E1 and terminal Tc. See Figure. Turn ignition on. Check open door indicator light for any trouble codes. If Codes 14 and 15 are present, go to next step. If no codes are present, check front passenger's door ECU. See FRONT PASSENGER'S DOOR ECU under PIN VOLTAGE TESTS.
- Disconnect driver's door and front passenger's door ECU connectors. Connect jumper wire between DLC2 terminal E1 and terminal Tc. See Figure. Turn ignition on. Check open door indicator light for any trouble codes. If Codes 14 and 15 are present, repair or replace wiring harness between driver's door ECU, body ECU and front passenger's door ECU. If no codes are present, repair or replace wiring harness between driver's door ECU, tilt/telescopic ECU and front passenger's door ECU.
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:
- • 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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