LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2004 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 106 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0120, DTC P0122, DTC P0123, DTC P0220, DTC P0222, DTC P0223 Or DTC P2135 >> Diagnosis & Repair (Using Lexus Scan Tool)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair (Using Lexus Scan Tool)

WARNING: This page is about a different car, the 2003 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect Lexus scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Turn scan tool on. Using Lexus scan tool, monitor throttle valve opening percentage at VTA circuit and voltage at VTA2 circuit. Opening percentage should be 64-96 percent and voltage should be 4.6-5.1 volts with a fully closed throttle. Depress accelerator pedal to floor (WOT). Opening percentage should be 8-20 percent and voltage should be 2-2.9 volts with a fully open throttle. If readings are within specification, replace ECM and retest. If readings are not within specification, go to next step.
  2. Access ECM at left front of engine compartment. Turn ignition on. Backprobing, measure voltage between terminals VC and E2 at ECM E5 connector. See Figure and Fig 1 . If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECM and retest.
    Fig 1: Checking Voltage Between ECM Connector Terminals VC & E2
    G00244903Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Turn ignition on. Backprobing, measure voltage between terminals VTA and E2 at ECM E5 and E2 connectors. Voltage should be .4-1.0 volt with throttle fully closed and 3.2-4.8 volts with throttle fully open. Backprobing, measure voltage between terminals VTA2 and E2 at ECM E5 and E2 connectors. See Fig 2. Voltage should be 2.0-2.9 volts with throttle fully closed and 4.6-5.1 volts with throttle fully open. If voltage is not as specified, go to next step. If voltage is as specified, replace ECM and retest.
    Fig 2: Checking Voltage Between Terminals VTA & E2, & VTA2 & E2 Of ECM Connectors
    G00244904Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Check TP sensor operation. See Fig 3. See SYSTEM & COMPONENT TESTING - GS300, GS430, IS300 & LS430 article. See THROTTLE POSITION SENSOR RESISTANCE  table. Replace TP sensor as necessary. If TP sensor is okay, check for short or open circuit in wiring harness between ECM E2 and E5 connector and TP sensor. Repair wiring as necessary.
    THROTTLE POSITION SENSOR RESISTANCE

    Throttle Position Sensor Terminal Resistance
    VC (1) - E2 (4) 1.2-3.2 Ohms @ 68°F (20°C)
    VTA (2) - E2 (4) 1.8-10.5 Ohms @ 68°F (20°C)
    VTA2 (3) - E2 (4) 1.8-10.5 Ohms @ 68°F (20°C)
    Fig 3: Checking Throttle Position Sensor
    G00244905Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About LEMON Manuals