Millimeter Wave Radar Sensor Power Source Circuit

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





INSPECTION PROCEDURE

NOTICE:
* When the distance control ECU is replaced with a new one, Initialization must be performed Installation.
* When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed Adjustments.

PROCEDURE

1. CHECK DISTANCE CONTROL ECU (IGB VOLTAGE)





(a) Disconnect the millimeter wave radar sensor connector.

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

Standard Voltage:





Text in Illustration





(c) Reconnect the millimeter wave radar sensor connector.

NG -- CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - DISTANCE CONTROL ECU)
OK -- Continue to next step.

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

(a) Disconnect the millimeter wave radar sensor connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:





(d) Reconnect the millimeter wave radar sensor connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR - BODY GROUND)

(a) Disconnect the millimeter wave radar sensor connector.

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

Standard Resistance:





(c) Reconnect the millimeter wave radar sensor connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR - BODY GROUND)

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Dynamic Radar Cruise Control System

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

(a) Disconnect the millimeter wave radar sensor connector.

(b) Disconnect the distance control ECU connector.

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

Standard Resistance:





(d) Reconnect the millimeter wave radar sensor connector.

(e) Reconnect the distance control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE DISTANCE CONTROL ECU Removal