Navigation System Steering Pad Switch Circuit

Body Electrical. Lexus Is250, Is220D. Gse20 Ale20
Navigation. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT RADIO RECEIVER

INSPECT STEERING PAD SWITCH ASSEMBLY

INSPECT SPIRAL CABLE

NAVIGATION SYSTEM - Steering Pad Switch Circuit


DESCRIPTION

This circuit sends an operation signal from the steering pad switch to the radio receiver.
If there is an open in the circuit, the navigation system cannot be operated using the steering pad switch.
If there is a short in the circuit, the resulting condition is the same as if the switch were continuously depressed. Therefore, the navigation system cannot be operated using the steering pad switch, and the navigation system itself cannot function.

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Navigation.Navigation System.Navigation System Steering Pad Switch Circuit


INSPECTION PROCEDURE

NOTICE:
The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the precautionary notice for the Supplemental Restraint System (Click here).
1.INSPECT RADIO RECEIVER


    Lexus Is250, Is220D. Gse20 Ale20.Navigation.Navigation System.Navigation System Steering Pad Switch Circuit

  1. Disconnect the radio receiver connector J63.

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

    Standard resistance:
    Tester connection
    		Condition
    		Specified condition
    SW1 - SWG
    		No switch is pushed
    		Approx. 100 kΩ
    SW1 - SWG
    		SEEK+ switch: push
    		Approx. 0 Ω
    SW1 - SWG
    		SEEK- switch: push
    		Approx. 0.3 kΩ
    SW1 - SWG
    		VOL+ switch: push
    		Approx. 1 kΩ
    SW1 - SWG
    		VOL- switch: push
    		Approx. 3.2 kΩ
    SW2 - SWG
    		No switch is pushed
    		Approx. 100 kΩ
    SW2 - SWG
    		MODE switch: push
    		Approx. 0 Ω
    SW2 - SWG
    		VOICE switch: push
    		Approx. 3.2 kΩ
    SW2 - SWG
    		ON HOOK switch: push
    		Approx. 0.3 kΩ
    SW2 - SWG
    		OFF HOOK switch: push
    		Approx. 1 kΩ


NG
Go to step 2
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2.INSPECT STEERING PAD SWITCH ASSEMBLY


  1. Disconnect the steering pad switch assembly connector K1.


    Lexus Is250, Is220D. Gse20 Ale20.Navigation.Navigation System.Navigation System Steering Pad Switch Circuit

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

    Standard resistance:

    Tester connection
    		Condition
    		Specified condition
    AU1 - EAU
    		No switch is pushed
    		 Approx. 100 kΩ
    AU1 - EAU
    		SEEK+ switch: push
    		Approx. 0 Ω
    AU1 - EAU
    		SEEK- switch: push
    		Approx. 0.3 kΩ
    AU1 - EAU
    		VOL+ switch: push
    		Approx. 1 kΩ
    AU1 - EAU
    		VOL- switch: push
    		Approx. 3.2 kΩ
    AU2 - EAU
    		No switch is pushed
    		 Approx. 100 kΩ
    AU2 - EAU
    		MODE switch: push
    		Approx. 0 Ω
    AU2 - EAU
    		VOICE switch: push
    		Approx. 3.2 kΩ
    AU2 - EAU
    		ON HOOK switch: push
    		Approx. 0.3 kΩ
    AU2 - EAU
    		OFF HOOK switch: push
    		Approx. 1 kΩ


NG
REPLACE STEERING PAD SWITCH ASSEMBLY
OK


3.INSPECT SPIRAL CABLE


    Lexus Is250, Is220D. Gse20 Ale20.Navigation.Navigation System.Navigation System Steering Pad Switch Circuit

  1. Disconnect the steering pad switch assembly and spiral cable connectors.

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

    Standard resistance:
    Tester connection
    		Spiral Cable Position
    		Specified condition
    EAU - EAU
    		Center
    		Below 1 Ω
    2.5 rotations to the left
    2.5 rotations to the right
    AU1 - AU1
    		Center
    		Below 1 Ω
    2.5 rotations to the left
    2.5 rotations to the right
    AU2 - AU2
    		Center
    		Below 1 Ω
    2.5 rotations to the left
    2.5 rotations to the right
    NOTICE:
    The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the page shown in the brackets (Click here).


NG
REPLACE SPIRAL CABLE
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE - RADIO RECEIVER)