Lexus IS250 · Service Manual TRANSMISSION

Shift Paddle Switch Circuit

Circuit diagnosis

DESCRIPTION

When moving the shift lever into the S position using the transmission control switch, it is possible to switch the shift range position between "1" (first range) and "6" (sixth range).
Shifting up "+" once raises one shift range position, and shifting down "-" lowers one shift range position.

WIRING DIAGRAM

C109074E01

INSPECTION PROCEDURE


1. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - BODY GROUND)

  1. C126233E01
    Disconnect the steering pad switch connector and spiral cable connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    Specified Condition
    2 - Body ground
    Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2. INSPECT SPIRAL CABLE SUB-ASSEMBLY

  1. I039337E10
    Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    J24-2 - k1-6
    Always
    Below 1 Ω
    J24-9 - k1-2
    Always
    Below 1 Ω
    J24-10 - k1-3
    Always
    Below 1 Ω



NG
REPLACE SPIRAL CABLE SUB-ASSEMBLY
OK


3. INSPECT TRANSMISSION SHIFT SWITCH ASSEMBLY

  1. C126404E01
    Disconnect the switch wire connector from the transmission shift switch.

  1. Measure the resistance between each terminal when the paddle shift is moved to each position.

    Standard resistance:
    Paddle Shift Position
    Tester Connection
    Specified Condition
    Pull continuously
    "+"
    (Up shift)
    SFTU - ECC
    Below 1 Ω
    Release
    "+"
    (Up shift)

    10 kΩ or higher
    Pull continuously
    "-"
    (Down shift)
    SFTD - ECC
    Below 1 Ω
    Release
    "-"
    (Down shift)

    10 kΩ or higher



NG
REPLACE TRANSMISSION SHIFT SWITCH ASSEMBLY
OK


4. INSPECT SWITCH WIRE

  1. C129189E01
    Connect the switch wire connector to the transmission shift switch.

  1. Measure the resistance between each terminal when the paddle shift is moved to each position.

    Standard resistance:
    Paddle Shift Position
    Tester Connection
    Specified Condition
    Pull continuously
    "+"
    (Up shift)
    2 - 6
    Below 1 Ω
    Release
    "+"
    (Up shift)

    10 kΩ or higher
    Pull continuously
    "-"
    (Down shift)
    3 - 6
    Below 1 Ω
    Release
    "-"
    (Down shift)

    10 kΩ or higher



NG
REPLACE SWITCH WIRE
OK


5. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - ECM)

  1. C106187E14
    Connect the spiral cable connector and steering pad switch connector.

  1. Disconnect the ECM connector.

  1. Measure the resistance according to the value(s) in the table below when the paddle shift is moved to each position.

    Standard resistance:
    Paddle Shift Position
    Tester Connection
    Specified Condition
    Pull continuously
    "+"
    (Up shift)
    A6-30 (SFTU) - Body ground
    Below 1 Ω
    Release
    "+"
    (Up shift)

    10 kΩ or higher
    Pull continuously
    "-"
    (Down shift)
    A6-19 (SFTD) - Body ground
    Below 1 Ω
    Release
    "-"
    (Down shift)

    10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE


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