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 assembly. The millimeter wave radar sensor assembly emits radio waves toward 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. The ECU recognizes the millimeter wave radar sensor assembly via terminals LGND. If an open circuit occurs in the wire harness between terminals LGND, the ECM cannot recognize the millimeter wave radar sensor assembly. The ECM will prohibit 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.

PROCEDURE

1. CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY (POWER SOURCE)

(a) Disconnect the millimeter wave radar sensor assembly connector.





(b) Turn the engine switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the millimeter wave radar sensor assembly connector.

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

2. CHECK HARNESS AND CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - ECM)

(a) Disconnect the millimeter wave radar sensor assembly connector.





(b) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):

for 2GR-FSE





for 4GR-FSE





Standard Resistance (Check for Short):

for 2GR-FSE





for 4GR-FSE





Text in Illustration





(d) Reconnect the millimeter wave radar sensor assembly connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR ASSEMBLY - ECM)
OK -- Continue to next step.

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

(a) Disconnect the millimeter wave radar sensor assembly connector.





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

Standard Resistance (Check for Open):





Text in Illustration





(c) Reconnect the millimeter wave radar sensor assembly connector.

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

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

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

(a) Disconnect the millimeter wave radar sensor assembly connector.





(b) Disconnect the distance control ECU connector.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





Text in Illustration





(d) Reconnect the millimeter wave radar sensor assembly connector.

(e) Reconnect the distance control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (MILLIMETER WAVE RADAR SENSOR - DISTANCE CONTROL ECU)

OK -- REPLACE DISTANCE CONTROL ECU Removal