Dynamic Radar Cruise Control System Millimeter Wave Radar Sensor Power Source Circuit

Cruise Control System. Lexus Is250, Is220D. Gse20 Ale20
Cruise Control. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DISTANCE CONTROL ECU (IGB VOLTAGE)

CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - ECM AND BODY GROUND)

CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - DISTANCE CONTROL ECU)

DYNAMIC RADAR CRUISE CONTROL SYSTEM - Millimeter Wave Radar Sensor Power Source Circuit


DESCRIPTION

This circuit provides power to the millimeter wave radar sensor. The millimeter wave radar sensor emits radio waves towards an object in front and measures the distance and direction of the object by receiving the beam reflections. Based on the reflections, the sensor calculates the difference in speed between the vehicle and the object in front. This data is transmitted to the distance control ECU (cruise control ECU). The ECU recognizes the millimeter wave radar sensor via terminals LGND. If an open circuit occurs in the wire harness between terminals LGND, the ECM cannot recognize the millimeter wave radar sensor. The ECM will stop the control of the vehicle-to-vehicle distance control mode and only the constant speed control mode can be used.

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Millimeter Wave Radar Sensor Power Source Circuit


INSPECTION PROCEDURE

1.CHECK DISTANCE CONTROL ECU (IGB VOLTAGE)
Lexus Is250, Is220D. Gse20 Ale20.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Millimeter Wave Radar Sensor Power Source Circuit
  1. Disconnect the B9 sensor connector.

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

    Standard voltage:
    Tester Connection
    Condition
    Specified Condition
    B9-5 (IGB) - Body ground
    Engine switch on (IG)
    10 to 14 V


NG
Go to step 3
OK


2.CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - ECM AND BODY GROUND)
Lexus Is250, Is220D. Gse20 Ale20.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Millimeter Wave Radar Sensor Power Source Circuit
  1. Disconnect the B9 sensor connector.

  1. Disconnect the A5 ECM connector.

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

    Standard resistance:
    Tester Connection
    Specified Condition
    A5-29 (LGND) - B9-1 (LGND)
    Below 1 Ω
    B9-1 (LGND) - Body ground
    10 kΩ or higher
    B9-2 (SGND) - Body ground
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

3.CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - DISTANCE CONTROL ECU)
Lexus Is250, Is220D. Gse20 Ale20.Cruise Control.Cruise Control System.Dynamic Radar Cruise Control System  Millimeter Wave Radar Sensor Power Source Circuit
  1. Disconnect the B9 sensor connector.

  1. Disconnect the J17 ECU connector.

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

    Standard resistance:
    Tester Connection
    Specified Condition
    B9-5 (IGB) - J17-13 (IGB)
    Below 1 Ω
    J17-13 (IGB) - Body ground
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE