2004 Lexus GX 470FACTORY OEM SERVICE PROCEDURE

SFI System (2UZ-FE): Inspection

  1. INSPECT MASS AIR FLOW METER 
    1. Output voltage inspection.
      1. Apply battery voltage across terminals 3 (+B) and 4 (E2G).
      2. Connect the positive (+) tester prove to terminal 5 (VG), and negative (-) tester prove to terminal 4 (E2G).
      3. Blow air into the MAF meter, and check if the voltage fluctuates.
    2. Resistance inspection.
      1. Using an ohmmeter, measure resistance between the terminals 2 (THA) and 1 (E2).

      Resistance: 

      1. 12.5-16.9 kΩ at -20°C (-4°F) 
      2. 2.19-2.67 kΩ at 20°C (68°F) 
      3. 0.50-0.68 kΩ at 60°C (140°F) 
      Fig 1: Identifying MAF Sensor Terminals & Resistance Values
      G00918168Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. INSPECT THROTTLE W/MOTOR BODY ASSY 
    1. Disconnect the throttle control motor connector.
    2. Using an ohmmeter, measure the motor resistance between terminal M+ and M-.
      1. Motor resistance: 0.3-100 Ω at 20 °C (68 °F) 
      Fig 2: Measuring Motor Resistance Between Throttle Control Motor Terminals M+ & M-
      G00918169Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT KNOCK SENSOR 
    1. Continuity inspection.
      1. Using an ohmmeter, check that these is no continuity between the terminal and body.
      1. Specified condition: No continuity
      Fig 3: Checking Knock Sensor Resistance
      G00918170Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT ENGINE COOLANT TEMPERATURE SENSOR 
    1. Resistance inspection.
      1. Using an ohmmeter, measure the resistance between terminals.

      Resistance: 

      1. 2.32 - 2.59 kΩ at 20 °C (68 °F) 
      2. 0.310 - 0.326 kΩ at 80 °C (176 °F) 
      NOTE: When inspecting the water temperature sensor in water, prevent water flow into the terminals. After inspection, wipe the water off from the sensor.
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.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

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.