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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step  6.
  2. Connect hand-held tester to Data Link Connector (DLC) No. 3 at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester on. Using hand-held tester, monitor NSW, REVERSE, 2ND and LOW signals while moving shift lever into Park, Reverse, Neutral, "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. ECM is located behind glove box, near passenger's side kick panel. See Figure.
    INPUT SIGNAL DISPLAYS

    Shift Lever Position Signal Display
    Park & Neutral NSW OFF-ON
    Reverse REVERSE OFF-ON
    Low LOW OFF-ON
    2 2ND OFF-ON
  3. Disconnect electrical connector from PNP switch. PNP switch is located on side of transaxle. Note PNP switch terminal identification. See Fig 1. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS  table.
  4. If proper continuity exists, go to next step. If proper continuity does not exist, adjust or replace switch as necessary. For adjustment or replacement procedures for PNP switch, adjustment of PNP switch, see PARK/NEUTRAL POSITION SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
    PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

    Shift Lever Position Continuity Between Terminals No.
    Park 2 & 7; 5 & 6
    Reverse 2 & 8
    Neutral 2 & 9; 5 & 6
    Drive 2 & 10
    2 2 & 3
    Low 2 & 4
    Fig 1: Identifying Park/Neutral Position Switch Terminals
    G95C32526Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. Check for defective wiring harness and electrical connectors between PNP switch and ECM, and between battery and PNP switch. See WIRING DIAGRAMS article. It may be necessary to consult wiring diagram in appropriate STARTERS article in STARTING & CHARGING SYSTEMS for additional PNP switch wiring. ECM is located behind glove box, near passenger's side kick panel. See Figure. Repair wiring harness or electrical connectors as necessary.
  6. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Turn ignition on. Using voltmeter, check voltage between body ground and specified terminal at ECM electrical connectors E6 and E7 in relation to shift lever position. See PARK/NEUTRAL POSITION SWITCH VOLTAGE  table. See Figure. If voltage is not within specification, go to next step. If voltage is within specification, replace ECM.
    PARK/NEUTRAL POSITION SWITCH VOLTAGE

    Shift Lever Position ECM Electrical Connector & Terminal No. (1) Volts
    Park & Neutral E6 Terminal No. 8 0
    E6 Terminal No. 13 0
    E6 Terminal No. 14 0
    E7 Terminal No. 20 0
    Reverse E6 Terminal No. 8 (2) 9-14
    E6 Terminal No. 13 0
    E6 Terminal No. 14 0
    E7 Terminal No. 20 (2) 9-14
    Drive E6 Terminal No. 8 0
    E6 Terminal No. 13 0
    E6 Terminal No. 14 0
    E7 Terminal No. 20 9-14
    2 E6 Terminal No. 8 0
    E6 Terminal No. 13 0
    E6 Terminal No. 14 9-14
    E7 Terminal No. 20 9-14
    Low E6 Terminal No. 8 0
    E6 Terminal No. 13 9-14
    E6 Terminal No. 14 0
    E7 Terminal No. 20 9-14
    (1) For ECM electrical connector terminal identification, see Figure.
    (2) Voltage may be slightly less due to illumination of back-up lights.
  7. Disconnect electrical connector from PNP switch. PNP switch is located on side of transaxle. Note PNP switch terminal identification. See Fig 1. Using ohmmeter, check for continuity between specified terminals with shift lever in proper positions. See PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS  table.
  8. If proper continuity exists, go to next step. If proper continuity does not exist, adjust or replace PNP switch as necessary. For adjustment or replacement procedures for PNP switch, see PARK/NEUTRAL POSITION SWITCH under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
  9. Check for defective wiring harness and electrical connectors between PNP switch and ECM, and between battery and PNP switch. See WIRING DIAGRAMS article. It may be necessary to consult wiring diagram in appropriate STARTERS article in STARTING & CHARGING SYSTEMS for additional PNP switch wiring. Repair wiring harness or electrical connectors as necessary.
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