Dynamic Radar Cruise Control System Cruise Control Switch Circuit

Cruise Control System. Lexus Gs430, Gs300. Uzs190 Grs190
Cruise Control. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

INSPECT CRUISE CONTROL MAIN SWITCH

INSPECT SPIRAL CABLE

CHECK WIRE HARNESS (SPIRAL CABLE - ECM)

CHECK WIRE HARNESS (SPIRAL CABLE - BODY GROUND)

DYNAMIC RADAR CRUISE CONTROL SYSTEM - Cruise Control Switch Circuit


DESCRIPTION

The cruise control main switch operates 8 functions: SET, COAST, TAP-DOWN, RESUME, ACCEL, TAP-UP, CANCEL and MODE. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP and ACCEL functions are operated with the same switch. The cruise control main switch is an automatic return type switch which turns on only while operating it in each arrow direction and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. The ECM then reads the resistance value that has been changed by the switch operation to control MODE, SET, COAST, RESUME, ACCEL and CANCEL. The dynamic radar cruise control system has two cruise control modes: the constant speed control mode and vehicle-to-vehicle distance control mode.
HINT:
  1. The vehicle-to-vehicle distance control mode is always selected when starting up the dynamic radar cruise control system.
  2. The operation of the constant speed control mode is the same as that for a conventional cruise control system.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER
Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit
  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester main switch ON.

  1. Check the Data List for proper functioning of the cruise control main switch.

    ECM (Cruise control):
    Item
    Measurement Item / Display (Range)
    Normal Condition
    Diagnostic Note
    Main SW (Main)
    Main switch signal (Main CPU) / ON or OFF
    ON: Main switch ON (pushed on)
    OFF: Main switch OFF (pushed off)
    -
    Cancel SW
    Cancel switch signal / ON or OFF
    ON: CANCEL switch ON
    OFF: CANCEL switch OFF
    -
    SET/COAST SW
    SET/COAST switch signal / ON or OFF
    ON: SET / COAST switch ON
    OFF: SET / COAST switch OFF
    -
    RES/ACC SW
    RES/ACC switch signal / ON or OFF
    ON: RES / ACC switch ON
    OFF: RES / ACC switch OFF
    -
    OK:
    When cruise control main switch operation is performed, the result will be same as above.

    Result:
    Result
    Proceed to
    OK
    A
    NG (all items are defective)
    B
    NG (1 to 3 items are defective)
    C


A
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE CRUISE CONTROL MAIN SWITCH
B


2.INSPECT CRUISE CONTROL MAIN SWITCH

Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit

  1. Disconnect the cruise control main switch connector.

  1. Measure the resistance of the connector.


Standard resistance:

Tester Connection
Switch Condition
Specified Condition
1 - 2, 1 - 3
Neutral
10 kΩ or higher
1 - 3
RES/ACC
235 to 245 Ω
1 - 3
SET/COAST
620 to 640 Ω
1 - 3
Cancel
1510 to 1570 Ω
1 - 3
Main Switch OFF
10 kΩ or higher
1 - 3
Main Switch OFF
Below 1 Ω
1 - 2
MODE
Below 1 Ω


NG
REPLACE CRUISE CONTROL MAIN SWITCH
OK


3.INSPECT SPIRAL CABLE
Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit
  1. Disconnect the A and L20 spiral cable connectors.

  1. Measure the resistance of the connectors.

    Standard resistance:
    Tester Condition
    Specified Condition
    A-1 - L20-7
    Below 1 Ω
    A-3 - L20-1
    Below 1 Ω
    A-4 - L20-2
    Below 1 Ω


NG
REPLACE SPIRAL CABLE
OK


4.CHECK WIRE HARNESS (SPIRAL CABLE - ECM)
Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit
  1. Disconnect the A6 and A7 ECM connectors.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    L20-1 - A7-31 (CCS)
    Always
    Below 1 Ω
    L20-7 - A6-20 (CCHG)
    Always
    Below 1 Ω
    L20-1 - Body ground
    Always
    10 kΩ or higher
    L20-7 - Body ground
    Always
    10 kΩ or higher


NG
REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR
OK


5.CHECK WIRE HARNESS (SPIRAL CABLE - BODY GROUND)
Lexus Gs430, Gs300. Uzs190 Grs190.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Cruise Control Switch Circuit
  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    Condition
    Specified Condition
    L20-2 - Body ground
    Always
    Below 1 Ω


NG
REPAIR OR REPLACE WIRE HARNESS AND CONNECTOR
OK

REPLACE ECM