Diagnosis & Repair (Using OBD-II Scan Tool)

2004 Toyota Matrix XR, FWD, StandardSECTION Diagnosis & Repair (Using OBD-II Scan Tool)
WARNING: This page is about a different car, the 2003 Lexus SC 430, 2003 Lexus LS 430, 2003 Lexus IS 300, 2003 Lexus GS 430, and 2003 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
  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 SC430, terminal No. 12 (White/Blue wire) at ECM connector E6. 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 SYMPTOMS in TROUBLE SHOOTING - NO CODES article.
  3. Check for open in wiring harness between ECM and starter relay. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary. If wiring is okay, replace ECM and retest.
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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.