2001 Lexus LS 430FACTORY OEM SERVICE PROCEDURE

Diagnosis & Repair (Using OBD-II Scan Tool)

  1. Access ECM at left front of engine compartment. Backprobing ECM connector, measure voltage between ground and following terminal:
    • On GS300, terminal No. 2 (Black wire) at ECM connector E5. See Figure.
    • On IS300, terminal No. 2 (Black wire) at ECM connector E4. See Figure.
    • On GS430, terminal No. 12 (Black wire) at ECM connector E6. See Figure.
    • On LS430, terminal No. 12 (Blue/Orange wire) at ECM connector E3. See Figure.

    On all models, go to next step.

  2. Turn ignition switch to START position. With starter being cranked, voltage should be 6 volts or more. If voltage is not as specified, go to next step. If voltage is as specified, no problem is indicated at this time. Diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
  3. Check for open in wiring harness between ECM and starter relay. See WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, replace ECM and retest.
Factory Service Tools

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:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.