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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect Toyota hand-held tester or scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on and then turn hand-held tester or scan tool on. Using hand-held tester or scan tool, monitor NSW, REVERSE, 2ND and LOW signals while moving shift lever into Park, Reverse, Neutral, Drive "2" and Low. Ensure signals are properly displayed in relation to shift lever position. See INPUT SIGNAL DISPLAYS  table. If signals are not properly displayed, go to next step. If signals are properly displayed, replace ECM.
    INPUT SIGNAL DISPLAYS

    Shift Lever Position Signal Display
    Park & Netural NSW OFF-ON
    Reverse REVERSE OFF-ON
    Drive DRIVE OFF-ON
    2 2ND OFF-ON
    Low LOW OFF-ON
  2. Disconnect PNP switch harness connector. Check continuity between appropriate PNP switch terminals (component side) with shift lever in appropriate position. See PARK/NEUTRAL POSITION SWITCH CONTINUITY  table. See Fig 1. If problem does not exist, go to next step. If problem exists, replace PNP switch.
    PARK/NEUTRAL POSITION SWITCH CONTINUITY

    Shift Lever Position Continuity Between Terminals No.
    Park 1 & 3; 6 & 9
    Reverse 2 & 3
    Neutral 3 & 5; 6 & 9
    Drive 3 & 7
    2 3 & 4
    Low 3 & 8
  3. Check wiring between battery and PNP switch and between PNP switch and ECM. See WIRING DIAGRAMS article. It may be necessary to consult wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS for additional PNP switch wiring. If problem exists, repair wiring as necessary. If problem does not exist, replace ECM.
Fig 1: Identifying Park/Neutral Position Switch Terminals (Component Side)
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