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Home >> Lexus >> 2005 >> IS 300 Base, Automatic >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission - Diagnostics >> Problem Symptoms Table >> Transmission Shift Switch Circuit >> Inspection Procedure
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Inspection Procedure

  1. Check shift lock control ECU (E-shift main switch) (See  DTC P0705 Transmission Range Sensor Circuit Malfunction (PRNDL Input)  ). 

    NG: Replace the shift lock control ECU (E-shift main switch) (See  FLOOR SHIFT ASSEMBLY  ). 

    OK: Go to next step. 

  2. Check operation of transmission shift switch. 

    PREPARATION: 

    1. Turn the ignition switch to ON.
    2. Shift the shift lever into the M position.

    CHECK: 

    Check the odo trip display panel when the transmission shift switch is pressed.

    OK: 

    OPERATION OF TRANSMISSION SHIFT SWITCH

    Switch condition Odo trip display panel
    "Up" switch press Shift up
    "Down" switch press Shift down

    NG: Go to step 3. 

    OK: Replace the ECM (See  ENGINE CONTROL MODULE (ECM)  ). 

  3. Check voltage between each of terminals SFTU, SFTD and E1 of ECM. 

    PREPARATION: 

    1. Turn ignition switch to ON.
    2. Remove the ECM with connectors still connected.

    CHECK: 

    Check voltage between each terminal of SFTU or SFTD and E1 of ECM.

    OK: 

    SFTU, SFTD AND E1

    Switch Condition Tester Connection Specified Condition
    "Up" switch held pressed E4-6 (SFTU) - E6-7 (E1) Below 3 V
    "Up" switch released E4-6 (SFTU) - E6-7 (E1) 7 to 14 V
    "Down" switch held pressed E4-5 (SFTD) - E6-7 (E1) Below 3 V
    "Down" switch released E4-5 (SFTD) - E6-7 (E1) 7 to 14 V
    Fig 1: Checking Voltage Between Each Of Terminals SFTU, SFTD And E1 Of ECM
    G02947672Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step 4. 

    OK: Proceed to next circuit inspection shown in problem symptoms table (See  PROBLEM SYMPTOMS TABLE  ). 

  4. Check transmission shift switch. 

    PREPARATION: 

    1. Remove the steering wheel pad.
    2. Disconnect the transmission shift switch connector.

    CHECK: 

    Check resistance between each terminal of transmission shift switch connector.

    OK: 

    TRANSMISSION SHIFT SWITCH

    Switch Condition Tester Connection Specified Condition
    "Up" switch pressed 4-2 Below 1 Ω
    "Up" switch released 4-2 10 kΩ or higher
    "Down" switch pressed 4-1 Below 1 Ω
    "Down" switch released 4-1 10 kΩ or higher
    Fig 2: Checking Transmission Shift Switch
    G02947673Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Replace the transmission shift switch (See  TILT STEERING COLUMN  1). 

    OK: Repair or replace harness or connector (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ).